• Title/Summary/Keyword: delay index

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The Pandemic League of COVID-19: Korea Versus the United States, With Lessons for the Entire World

  • Issac, Alwin;Stephen, Shine;Jacob, Jaison;VR, Vijay;Radhakrishnan, Rakesh Vadakkethil;Krishnan, Nadiya;Dhandapani, Manju
    • Journal of Preventive Medicine and Public Health
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    • v.53 no.4
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    • pp.228-232
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    • 2020
  • Coronavirus disease 2019 (COVID-19) is inflicting a brutal blow on humankind, and no corner of the world has been exempted from its wrath. This study analyzes the chief control measures and the distinctive features of the responses implemented by Korea and the United States to contain COVID-19 with the goal of extracting lessons that can be applied globally. Even though both nations reported their index cases on the same day, Korea succeeded in flattening the curve, with 10 752 cases as of April 28, 2020, whereas the outbreak skyrocketed in the United States, which had more than 1 million cases at the same time. The prudent and timely execution of control strategies enabled Korea to tame the spread of the virus, whereas the United States paid a major price for its delay, although it is too early to render a conclusive verdict. Information pertaining to the number of people infected with the virus and measures instituted by the government to control the spread of COVID-19 was retrieved from the United States Centers for Disease Control and Prevention and the Korea Centers for Disease Control and Prevention websites and press releases. Drawing lessons from both nations, it is evident that the resolution to the COVID-19 pandemic lies in the prudent usage of available resources, proactive strategic planning, public participation, transparency in information sharing, abiding by the regulations that are put into place, and how well the plan of action is implemented.

Feedback Scheme for STBC-Spatial Multiplexing OFDM System with outdated channel feedback (지연된 귀환 채널 정보를 가지는 STBC-공간다중화 OFDM 시스템을 위한 귀환 기법)

  • Lim Jong-Kyoung;Hwang Hyeon-Chyeol;Seo Myoung-Seok;Kwak Kyung-Sup
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.4 s.346
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    • pp.31-38
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    • 2006
  • In this paper, we propose an efficient preceding scheme for STBC-Spatial Muiltiplexing OFDM systems. In MIMO systems, the precoder is designed on the assumption that feedback channel information is perfectly known to transmitter and receiver. However, feedback delay and link errors in real environment make the transmitter use the incorrect channel information and consequently cause the performance degradation. The proposed precoder is designed to compensate for the performance degradation by the diversity gain provided by STBC. At the transmitter, the precoder for each subcarrier is constructed by using the index of codebook, subcarrier correlation, and auto correlation of channel. From the simulation results, STBC-spatial multiplexing OFDM outperforms the preceded-spatial multiplexing OFDM at $SER=10^{-3}$ when the Doppler frequency is greater than 60Hz.

A Study on the Combustion of Blended Fuel Oil in a Diesel Engine for Small-Sized Fishing Boat (소형 어선용 디이젤 기관의 혼합연료유 연소에 관한 연구)

  • Go, Dae-Gwon;An, Su-Gil
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.23 no.2
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    • pp.72-79
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    • 1987
  • In this paper, an investigation of the property of blended fuel oil, combustion characteristics and engine performance was made, in case blended fuel oil(light oil+heavy oil) was used in a home-made precombustion diesel engine for small-sized fishing boat. The results may be summarized as follows: 1. The specific gravity was linearly increased in accordance with the increase in heavy oil ratio in blended fuel oil, and the relationship between viscosity and temperature was coincided with the formula of Walther-ASTM, and the CCAI, the ignition quality index, was increased nearly as a straight line of the gradient 1.0. 2. The ignition delay was slightly increased below 810 of CCAI(blending ratio to be 60% of heavy oil), but remarkably increased above 810 of CCAI. Therefore, it was considered that the practicable value of CCAI, ignition quality of blended fuel oil, was more than 810. 3. The maximum combustion pressure was increased until blending ratio of heavy oil was raised up to 40%. On the contrary, it came to be decreased at that ratio, with smoke emissions remarkably increasing above 60%. Therefore, it was found in this experiment that the best practicable limit of heavy oil blending ratio was around 50% for saving fuel costs with least smoke emissions.

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A Study on the Combustion of Blended Fuel Oil in a Diesel Engine for Small-Sized Fishing Boat (소형 어선용 디이젤 기관의 혼합연료유 연소에 관한 연구)

  • Dae-Kwon Ko;Soo-Kil Ahn
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.23 no.2
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    • pp.26-26
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    • 1987
  • In this paper, an investigation of the property of blended fuel oil, combustion characteristics and engine performance was made, in case blended fuel oil(light oil+heavy oil) was used in a home-made precombustion diesel engine for small-sized fishing boat. The results may be summarized as follows: 1. The specific gravity was linearly increased in accordance with the increase in heavy oil ratio in blended fuel oil, and the relationship between viscosity and temperature was coincided with the formula of Walther-ASTM, and the CCAI, the ignition quality index, was increased nearly as a straight line of the gradient 1.0. 2. The ignition delay was slightly increased below 810 of CCAI(blending ratio to be 60% of heavy oil), but remarkably increased above 810 of CCAI. Therefore, it was considered that the practicable value of CCAI, ignition quality of blended fuel oil, was more than 810. 3. The maximum combustion pressure was increased until blending ratio of heavy oil was raised up to 40%. On the contrary, it came to be decreased at that ratio, with smoke emissions remarkably increasing above 60%. Therefore, it was found in this experiment that the best practicable limit of heavy oil blending ratio was around 50% for saving fuel costs with least smoke emissions.

The Preventive Effects of Nanopowdered Peanut Sprout-added Caciocavallo Cheese on Collagen-induced Arthritic Mice

  • Kim, Dong-Hwi;Chang, Yoon Hyuk;Kwak, Hae-Soo
    • Food Science of Animal Resources
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    • v.34 no.1
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    • pp.49-56
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    • 2014
  • The present study was carried out to investigate the effects of nanopowdered peanut sprout-added Caciocavallo cheese (NPCC) on the prevention and treatment of rheumatoid arthritis in DBA/IJ mice immunized with type II collagen. After the induction of arthritis, the mice were being divided into five groups: (1) normal, no immunization; (2) CIA, collagen-induced arthritis; (3) MTX, collagen-induced arthritis treated with methotrexate (0.3 mg/kg body weight); (4) CC, collagen-induced arthritis treated with Caciocavallo cheese (0.6 g/d); (5) NPCC, collagen-induced arthritis treated with nanopowdered peanut sprout-added Caciocavallo cheese (0.6 g/d). Nanopowdered peanut sprout was ranged from 300 to 350 nm, while regular powdered peanut sprouts were ranged from 50 to $150{\mu}m$. The NPCC group had considerable reductions of clinical scores and paw thicknesses at the end of experiment as compared to the CIA group. In the serum analysis, the TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and $IgG_1$ levels in the NPCC group have decreased by 69.4, 75.9, 66.6, and 61.9%, respectively, when compared to the CIA group. The histological score and spleen index of the NPCC group were significantly lower than the CIA group. In conclusion, the feeding NPCC method could delay and/or prevent the rheumatoid arthritis in the collagen-induced arthritis mouse model. Based on this study, nanopowdered peanut sprouts could be applied to various functional cheeses.

SRN Hierarchical Modeling for Packet Retransmission and Channel Allocation in Wireless Networks (무선망에서 패킷 재전송과 채널할당 성능분석을 위한 SRN 계층 모델링)

  • 노철우
    • The KIPS Transactions:PartC
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    • v.8C no.1
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    • pp.97-104
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    • 2001
  • In this paper, we present a new hierarchical model for performance analysis of channel allocation and packet service protocol in wireless n network. The proposed hierarchical model consists of two parts : upper and lower layer models. The upper layer model is the structure state model representing the state of the channel allocation and call service. The lower layer model, which captures the performance of the system within a given structure state, is the wireless packet retransmission protocol model. These models are developed using SRN which is an modeling tool. SRN, an extension of stochastic Petri net, provides compact modeling facilities for system analysis. To get the performance index, appropriate reward rates are assigned to its SRN. Fixed point iteration is used to determine the model parameters that are not available directly as input. That is, the call service time of the upper model can be obtained by packet delay in the lower model, and the packet generation rates of the lower model come from call generation rates of the upper model.

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Application of time-of-flight near infrared spectroscopy to Satsuma mandarin

  • Tsuchikawa, Satoru;Ito, Satomi;Inoue, Kinuyo;Miyamoto, Kumi
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1627-1627
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    • 2001
  • In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M^{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima t and the variation of full width at half maximum w were strongly dependent on the detection position and the wavelength of the laser beam. At, t and w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

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Application of time-of-flight near infrared spectroscopy to Satsuma mandarin

  • Tsuchikawa, Satoru;Ito, Satomi;Inoue, Kinuyo;Miyamoto, Kumi
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1626-1626
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    • 2001
  • In this study, a newly constructed optical measurement system, whose main components were a parametric tunable laser and a near infrared photoelectric multiplier, was applied to detection of the information for the inside of Satsuma mandarin using time-of-flight near infrared spectroscopy (TOF-NIRS). The combined effects on the time resolved profile of sample diameter, sugar content, the wavelength of the laser beam, and the detection position of transmitted light were investigated in detail. The samples used were Satsuma mandarin (Citrus unshu $M_{ARC}$.) (location: Wakayama, Japan) having the diameters of 50-84 mm. The sugar content measured by a refractometer varied from 9.9 to 16.3 Brix%. Equator of sample was irradiated vertically with the pulsed laser, and transmitted output power was measured on the restricted position of the equator using the optical fiber cable. The sampling time and the number of averaging the output power were 100 ns and 100 times, respectively. The variation of the attenuance of peak maxima At, the time delay of peak maxima $\Delta$t and the variation of full width at half maximum Δw were strongly dependent on the detection position and the wavelength of the laser beam. At, $\Delta$t and $\Delta$w increased gradually as the sample diameter increased to be much absorbed and vigorously scattered. On the other hand, each optical parameter had a tendency to increase as the sugar content increased. Such behavior was remarkable when the transmitted light was detected at the side face of a sample. When we apply TOF-NIRS to detection of the information for the inside of fruit with high moisture content like Satsuma mandarin, it is very important to give attention to the difference in the scattered light within tissues and the semi-straightly propagated light. Furthermore, we tried to express the resulting phenomena by using a model samples composed of water, sucrose, and milk. The variation of the time resolved profile is strongly governed by the combination of the light absorption component, scattering medium, and refractive index.

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Estimation for application of the Runoff Analysis using TOPMODEL at an ungaged watershed (미계측유역에 대한 TOPMODEL의 적용성 평가)

  • Kang, Sung-Jun;Park, Young-Gi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.3
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    • pp.1458-1464
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    • 2011
  • This study is on the application of TOPMODEL-topographic based hydrologic model-to the runoff analysis, The test area was the ssang-chi watershed which is mountainous catchment located in the upstream of the sumjin-gang basin and the watershed area is $126.7km^2$. The six's hourly runoff and precipitation data was selected in the 2006 ~ 2009 year. And the model parameters are calibrated using observed runoff data by Pattern Search method. The topographic index of the ssang-chi catchment was produced by digital elevation model(DEM) of 100m grid. As a results of the analysis, the parameters of model, a decay facter(m), transmissivity(T0), and the unsaturated zone delay(TD) are sensible to hydrologic response, and the simulated runoff data are in good agreement with observed runoff data.

A Survey on Rehabilitation Therapists' Understandings about Traditional Korean Medicine Treatments for Developmentally Delayed Children (발달지연 아동의 한방치료에 대한 소아재활치료사들의 인식조사)

  • Kweon, Ji Hyeon;Yun, Young Ju;Oh, Tae Young;Kim, Bu Young;Lee, Mi Joo;Lee, Seung Yeon;Yu, Sun Ae
    • The Journal of Pediatrics of Korean Medicine
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    • v.31 no.4
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    • pp.61-70
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    • 2017
  • Objectives The purpose of this survey is to know the rehabilitation therapists' awareness on the oriental medicine treatments for developmentally delayed children. Methods We distributed questionnaires to 370 rehabilitation therapists and collected 260 of them. We analyzed the data from the collected 260 questionnaires. Results 1. 60% of the participants didn't know what the oriental medicine treatment pertains. 2. 28% of the participants were aware the benefits of the oriental medicine treatment, especially in improving physical fitness and general health. 3. 30% of the participants worried about the side effect of the oriental medicine treatment such as increasing liver somatic index, changing of body weight, muscle stiffness or pain. 4. 53% of the participants said they refer to western medicine primary care doctor when parents of young patients ask rehabilitation therapists about the oriental medicine treatment option for their children. 5. Many participants think that the oriental treatment option should be widely recognized and understood. Conclusions This study shows that the rehabilitation therapists' low awareness about the oriental medicine treatment option for developmentally delayed children.