• Title/Summary/Keyword: Frequency of utilization

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ETS: Efficient Task Scheduler for Per-Core DVFS Enabled Multicore Processors

  • Hong, Jeongkyu
    • Journal of information and communication convergence engineering
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    • v.18 no.4
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    • pp.222-229
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    • 2020
  • Recent multi-core processors for smart devices use per-core dynamic voltage and frequency scaling (DVFS) that enables independent voltage and frequency control of cores. However, because the conventional task scheduler was originally designed for per-core DVFS disabled processors, it cannot effectively utilize the per-core DVFS and simply allocates tasks evenly across all cores to core utilization with the same CPU frequency. Hence, we propose a novel task scheduler to effectively utilize percore DVFS, which enables each core to have the appropriate frequency, thereby improving performance and decreasing energy consumption. The proposed scheduler classifies applications into two types, based on performance-sensitivity and allows a performance-sensitive application to have a dedicated core, which maximizes core utilization. The experimental evaluations with a real off-the-shelf smart device showed that the proposed task scheduler reduced 13.6% of CPU energy (up to 28.3%) and 3.4% of execution time (up to 24.5%) on average, as compared to the conventional task scheduler.

Novel Carrier-Based PWM Strategy of a Three-Level NPC Voltage Source Converter without Low-Frequency Voltage Oscillation in the Neutral Point

  • Li, Ning;Wang, Yue;Lei, Wanjun;Niu, Ruigen;Wang, Zhao'an
    • Journal of Power Electronics
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    • v.14 no.3
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    • pp.531-540
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    • 2014
  • A novel carrier-based PWM (CBPWM) strategy of a three-level NPC converter is proposed in this paper. The novel strategy can eliminate the low-frequency neutral point (NP) voltage oscillation under the entire modulation index and full power factor. The basic principle of the novel strategy is introduced. The internal modulation wave relationship between the novel CBPWM strategy and traditional SPWM strategy is also studied. All 64 modulation wave solutions of the CBPWM strategy are derived. Furthermore, the proposed CBPWM strategy is compared with traditional SPWM strategy regarding the output phase voltage THD characteristics, DC voltage utilization ratio, and device switching losses. Comparison results show that the proposed strategy does not cause NP voltage oscillation. As a result, no low-frequency harmonics occur on output line-to-line voltage and phase current. The novel strategy also has higher DC voltage utilization ratio (15.47% higher than that of SPWM strategy), whereas it causes larger device switching losses (4/3 times of SPWM strategy). The effectiveness of the proposed modulation strategy is verified by simulation and experiment results.

The Effects of Internet Utilization on the Life Satisfaction of the Elderly -The Mediating Effect of Social Activity- (노인의 인터넷활용이 생활만족도에 미치는 영향 -사회활동의 매개효과를 중심으로-)

  • Jeong, Kyu Hyoung;Yun, Ji Hee;Kim, Jong Sung
    • Korean Journal of Social Welfare Studies
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    • v.44 no.2
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    • pp.359-385
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    • 2013
  • The study looked into the effect of internet utilization (utilization frequency and utilization ability in internet) on the life satisfaction level for the elderly in depth. In order to verify the correlation of two variables, a mediating model structured by ego integrity was used which gave out the Seoul welfare panel data created by Seoul welfare foundation in 2010. The total sample size was a group of 1862 elders aged over 60. When it came to our research methods, structured equation analysis was applied to verify the mediating effect and theoretical background. The findings are as follows: First, elderly's utilization frequency in internet is not an influencing factor to life satisfaction and elderly's utilization ability in internet is an influencing factor to life satisfaction. Second, the level of social activity did function as partial mediator on relationship between elderly's utilization ability in internet and life satisfaction. This study indicates theoretical and practical interventions to promote elderly's utilization in internet.

The Solution of Insufficiency of Radio Frequency Spectrum in Republic of Kazakhstan

  • Abishev Olzhas;Jo Dong-Kwan;Chung Joong-Soo
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.549-554
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    • 2006
  • The objective of this paper is to propose a system by means of which the utilization of radio frequency spectrum may be improved from the state of extreme inefficiency at the present time in Kazakhstan to a state of efficiency and equilibrium in the future. The main solutions to efficiently use radio frequency spectrum in Kazakhstan will be described in this paper. There are 'Spectrum Utilization, Spectrum Sharing and Reuse the Spectrum' in which the radio frequency can be propagated in wide range using smalt amount of spectrum, or broadcast several channels via one spectrum sharing. In order to embed these systems in practice it will be better to make modifications consider Government policy and geographical and social requirements.

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Analysis of Appropriate Parameters for Piezoelectric Ceramic Utilization by Using BVD Model

  • Jeerapan, Chalermchai;Sriratana, Witsarut;Julsereewong, Prasit;Kummool, Sart
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2067-2070
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    • 2005
  • This paper presents an approach to evaluate the appropriate parameters for Piezoelectric ceramic utilization by adopting Impedance Method. Butterworth Van Dyke model (BVD) is considered to use as an equivalent circuit of Piezoelectric ceramic in case of no load. The experimental results from this model will be compared with the results from a circular Piezoelectric ceramic with 4.8 cm. diameter and 3 mm. thickness. The Thickness Mode vibration measured by Impedance Analyzer model 4192A can be analyzed from 1Hz to 13MHz for calculating and analyzing parameters at resonance frequency and anti-resonance frequency. These parameters are evaluated to design the efficient circuit for Piezoelectric ceramic utilization to obtain the optimal efficiency.

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Throughput Enhancement of C-RAN based on Adaptive Frequency Reuse

  • Lin, Zhi-feng;Joe, Inwhee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2016.04a
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    • pp.83-85
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    • 2016
  • C-RAN (Cloud Radio Access Network) structure is the most popular approach for 5G stander, it employs CoMP (Coordinated Multiple Points Transmission/Reception) to enhance frequency utilization and increase throughput for cell-edge users. C-RAN mainly includes two parts: baseband units (BBU) and remote radio heads (RRH). In this paper we propose a new resource block allocation (spectrum allocation) scheme by the permutation and combination of BBUs, and we also use the CoMP (Coordinated Multiple Points Transmission/Reception) technique according to the different environment to improve the spectrum utilization and reduce resource waste in different environment. The simulation results expound that the scheme significantly enhances throughput and improves the spectrum utilization.

A study on the utilization of a high school health clinic in Seoul (서울시내 일개 고등학교 학생들의 양호실 이용에 관한 조사)

  • Oh Jin Joo;Kim Eun Joo
    • Journal of Korean Public Health Nursing
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    • v.6 no.2
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    • pp.50-57
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    • 1992
  • This study was aimed at finding the status of utilization of school health clinic at a boy's high school in Seoul, from March 1988 to February 1990. Data were collected from the records of school health clinic. Major findings are as follows: 1. The average frequency of visits per person was 1.62, 1.92, 1.53 per a year respectively. 2. Students in grade two had the highest frequency of visits of the school health cliniclin.2 during 3years. 3. Injury was the most frequent type of complaint treated at the school health clinic and G-I trouble was the next. Cough with tonsilitis and e.t.c schowed no rate difference between years. 4. The rate of utilization was higher in April, June and September than other months, and lower in Feburary, December. In general, the type of complaints does not seem to be affected by season. 5. In weekday's utilization, the rate of Monday and Tuesday was highest. 6. The average hospital-refer rate for 3 years was $1.02\%$, and that of Injury was highest.

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Determinants Influencing the Utilization of the Rural Health Sub-centers (농촌지역 보건지소 이용에 영향을 미치는 요인 분석)

  • Kang, Jong-Doo
    • Journal of Preventive Medicine and Public Health
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    • v.23 no.3 s.31
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    • pp.316-323
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    • 1990
  • To analyze of determinants influencing the utilization of the rural health sub-centers (HSCs), 116 of 144 HSCs in Kyong Gi Do, were selected for this study. The self-administered questionnaire covering the environment and the characteristics of doctors working in the HSCs was sent to HSCs by mail. 105 questionnaires were returned of which 88 were completed and use in the study. The dependant variable was the total number of medical care visits to the HSCs from January 1, 1990 to March 31, 1990. Data was analyzed by multiple regression analysis. The results were as follows : First, the more time required to set from the HSCs to nearest hospital or clinic, the higher the utilization of the HSCs. Second, the more geographically accessible the HSCs was, the more utilization the HSCs. Third, the older of the HSCs doctors were, the more utilization of the HSCs. Fourth, the higher frequency of bus service from the HSCs to town, the more utilization of the HSCs. Fifth, the more time required from the HSCs to town, the more utilization of the HSCs. Therefore, the determinants influencing the utilization of the rural HSCs in Kyong-Gi Do, are mostly geographical accessibility of medical care.

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A Study on the Utilization Pattern and the Perception of Housewives about Edible Oil & Fats (주부들의 식용유지류 이용의식 및 사용실태)

  • 윤계순
    • Journal of the Korean Home Economics Association
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    • v.39 no.2
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    • pp.85-95
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    • 2001
  • This study was carried out to obtain the information concerning the perception and utilization patter of the housewives about the edible oil and fats. Data were obtained through questionnaires from 442 housewives in Chonbuk area. The eating frequency of food that used oil & fat was affected by age, residing area and educational level. family's preference score of food that used oil & fats was 3.34 point in the 5 point scale. 47% of the subjects answered that the intake rate of oil & fats had more from vegetable oils than animal sauces. Most of the subjects had negative response such as increased cholesterol and body weight for psychological state after the intake of food that used oil & fats. The main reason why some housewives did not use frequently oil & fats was inconvenience of tidying up. The kinds of the oil & fat used frequently were soybean oil, sesame oil, com oil and perilla oil. The nutrition knowledge score rotated to oil & fat was 7.62 point in the 10 point scale. The eating frequency of food that used oil & fats and its preference were positively correlated. These results indicate that the housewives haute a widespread tendency to pursue a health and convenience in the utilization of edible oil & fats.

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A Comparative Study on the Status and Utilization Types of Closed Schools in Rural and Islands - Comparative Study of Closed School in Goesan-gun, Chungcheongbuk-do, and Sinan-gun, Jeollanam-do - (농촌지역과 도서지역의 폐교 현황과 활용 유형 비교 연구 - 충청북도 괴산군과 전라남도 신안군 폐교를 중심으로 -)

  • Moon, Seang Hyen
    • Journal of the Korean Institute of Rural Architecture
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    • v.26 no.1
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    • pp.11-20
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    • 2024
  • Due to the decrease in the school-age population and the overall population, school closures will continue to occur. Currently, most school closures are happening in rural areas, where geographical conditions often result in relatively poor educational, welfare, and cultural facilities compared to urban areas. Additionally, the proportion of elderly populations and migrant women is continuously increasing. In order to effectively utilize closed schools in the future, various efficient utilization methods that align with the social context of the respective regions will be necessary. The purpose of this study is to examine the status of closed school and utilization types in selected rural and island areas of similar sizes through field surveys and literature reviews. By comparing and analyzing these findings, we have identified the predominant utilization types in rural and island areas and assessed the current situation where utilization is lacking. Based on the results, we aim to provide fundamental data for improving and enhancing the utilization of school closures in the face of the ongoing decline in the school-age population.