• Title/Summary/Keyword: MC method

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Another View Point on the Performance Evaluation of an MC-DS-CDMA System

  • Chen, Joy Iong-Zong;Hsieh, Tai Wen
    • Journal of Communications and Networks
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    • v.11 no.3
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    • pp.240-247
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    • 2009
  • The results of performance analysis by adopting the channel scenarios characterized as Weibull fading for an multicarrierdirect sequence-coded division multiple access (MC-DS-CDMA) system are proposed in this investigation. On the other hand, an approximate simple expression with the criterion of bit error rate (BER) versus signal-to-noise ratio (SNR) method is derived for an MC-DS-CDMA system combining with maximal ratio combining (MRC) diversity based on the moment generating function (MGF) formula of Weibull statistics, and it associates with an alternative expression of Gaussian Q-function. Besides, the other point of view on the BER performance evaluation of an MC-DS-CDMA system is not only the assumption of both single-user and multi-user cases applied, but the phenomena of partial band interference (PBI) is also included. Moreover, in order to validate the accuracy in the derived formulas, some of the system parameters, such as Weibull fading parameter (${\beta}$), user number (K), spreading chip number (N), branch number (L), and the PBI (JSR) values, etc., are compared with each other in the numerical results. To the best of author's knowledge, it is a brand new idea which proposes the evaluation of the system performance for an MC-DS-CDMA system over the point of view with Weibull fading channel.

Effects of the Progression Control of Myopia on Myopia Control Lenses and Single Vision Lenses (Myopia Control 렌즈와 Single Vision 렌즈의 근시진행 조절 효과)

  • Jung, Ji-Won;Lee, Ki-Seok;Yoo, Wang-Keun
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.1
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    • pp.19-26
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    • 2012
  • Purpose: This paper was to study the clinical effects of moderating myopia by comparing the myopia control lens, which was being recently recognized as a method of inhibiting the progression of myopia, with the wearers of single vision lens. Methods: Using 56 subjects between the ages of 8-15 years (112 eyes) with myopia in the areas of City of Daegu and Gyeongsangbuk Province as study subjects, refractive error, axial length, near point of convergence and accommodative near point were measured and compared a total of 3 times at the baseline, after 1-month and after 6-months. Results: For refractive error, suppression and mitigation were seen in the progression of spherical equivalent when MC lens was worn, as compared to using SV lens, and, when axial length MC lens was worn, the axial progression was significantly suppressed and delayed (p < 0.05). The near point of convergence became shorter with the use of MC lens, and the amplitude of convergence was improved when MC lens was worn. Accommodative near point became shorter with the use of MC lens, and focus ability was significantly improved (p <0.05). Conclusions: It was shown that MC lens, compared to SV lens, could alleviate myopia progression in school-age children and youth. It is considered that MC lens can be used as a useful therapy for the inhibition of myopia progression in the increasing number of myopic children and adolescents.

The Halliwick Method (할리윅 치료)

  • Kim, Tae-Youl;Yoon, Hee-Jong;Lambeck, Johan
    • Journal of Korean Physical Therapy Science
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    • v.5 no.3
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    • pp.625-631
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    • 1998
  • The Halliwick method was developed by Mr. James McMillan, a Canadian engineer of fluid mechanics. In 1949 he started to teach physically handicapped girls to swim at the "Halliwick school for crippled Girls" in London. The Halliwick method has four important basic units, as is shown in Fig 1. This constribution only deals with the structures or the practical part of the method. This part is also known as the 10-point programme. Before the characteristics of the 10 points are dealt with seperately, a few general remarks about these ponits have to be discussed. Of all things happening in the water, fun is the most important one. Swimming is fun! Swimming is taught in an order McMillan describes as: mental Adjustment(M.A), balance restoratiion(B.R.), inhibition(Inh.), and facilitation(Fac.). The 10 points of structure are linked to each other as well as to the learning process as is shown in Fig 3. The Halliwick method, which was devised by James McMillan, has proved to be a very successful way of establishing the basic principles as they have described in this article.

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An Interference Analysis Method with Site-Specific Path Loss Model for Wireless Personal Area Network

  • Moon, Hyun-Wook;Kwon, Se-Woong;Lee, Jong-Hyun;Yoon, Young-Joong
    • Journal of electromagnetic engineering and science
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    • v.10 no.4
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    • pp.290-295
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    • 2010
  • In this paper, an interference analysis method with a site-specific path loss model for a wireless personal area network (WPAN) is proposed. The site-specific path loss model is based on geometrical optics and geometric probability to consider both site-specific radio propagation characteristics and a closed-form expression to obtain the mean interference from which the uniformly distributed multiple interferers are derived. Therefore, the proposed interference analysis method can achieve more computational simplicity than the Monte-Carlo (MC) simulation, which uses the ray-tracing (RT) technique. In addition, better accuracy than the conventional interference analysis model that uses stochastic method can also be achieved. To evaluate the proposed method, a signal to the interference-noise ratio with a mean interference concept for uniformly distributed interferers is calculated and compared in two simulation scenarios. As a result, the proposed method produces not only better matched results with the MC simulation using the RT technique than the conventional interference analysis model, but also simpler and faster calculation, which is due to the site-specific path loss model and closed-form expression for interference calculation.

AN EXPERIMENTAL STUDY ON THE PHYSICAL PROPERTIES OF THE DENTURE BASE RESINS CURED BY MICROWAVE IRRADIATION (마이크로파 중합에 의한 의치상 레진의 물리적 성질에 관한 연구)

  • Kim, Hak Sun;Kim, Kwang Nam;Chang, Ik Tae
    • The Journal of Korean Academy of Prosthodontics
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    • v.28 no.2
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    • pp.109-124
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    • 1990
  • The purpose of this study was to investigate the physical propertise and determine whether three were any differences in the amount of porosity of the denture base resins cured by microwave irradiation and conventional water bath heating. The resins used in this study were K-33 resin and Acron MC resin. The properties selected were transverse strength, Knoop hardness, and density. A ten-power eyepiece and scanning electron microscope(Magnification of ${\times}$ 30and ${\times}$150)were used to examine the specimens for porosity. Through analyses of the data from this study, the following conclusions were obtained. 1. Microwave energy can be effectively use dtopolymerize poly(methylmethacrylate) denture base resins. 2. In the transverse strength, K-33 resin cured by microwave irradiation was the first highest, water bath cured K-33 resin the second, microwave cured Acron MC resin the third, water bath cured Acron MC resin the fourth. 3. In the Knoop hardness, K-33 resin cured by microwave irradiation was the first hardest, water bath cured K-33 resin the second, water bath cured Acron MC resin the third, microwave cured Acron MC resin the the fourth. 4. No significant difference was found between the density of resin denture bases polymerized by either method. 5. K-33 resin showed the most porosity for the microwave curing. But there was no significant difference in the Acron MC resin and other curing method.

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Effective Motion Compensation Method of H.264 on Multimedia Mobile System (멀티미디어 모바일 시스템에서의 효율적인 H.264 움직임 보간법)

  • Jeong, Dae-Young;Ji, Shin-Haeng;Park, Jung-Wook;Kim, Shin-Dug
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.10
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    • pp.467-473
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    • 2007
  • Power-aware design is one of the most important areas to be emphasized in multimedia mobile systems, in which data transfers dominate the power consumption. In this paper, we propose a new architecture for motion compensation (MC) of H.264/AVC with power reduction by decreasing the data transfers. For this purpose, a reconfigurable microarchitecture based on data type is proposed for interpolation and it is mapped onto the dedicated motion compensation IP (intellectual property) effectively without sacrificing the performance or the system latency. The original quarter-pel interpolation equation that consists of one or two half-pel interpolations and one averaging operation is designed to have different execution control modes, which result in decreasing memory accesses greatly and maintaining the system efficiency. The simulation result shows that the proposed method could reduce up to 87% of power consumption caused by data transfers over the conventional method in MC module.

Study on MC-CDMA Using Two-fold Orthogonal Frequency Overlap (이중 직교 주파수 중첩을 이용한 MC-CDMA변조방식에 관한 연구)

  • Ryu, Kwan-Wong;Park, Yong-Wan;Suh, Young-Suk;Kim, Ki-Chai
    • Journal of IKEEE
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    • v.3 no.1 s.4
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    • pp.141-149
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    • 1999
  • If signal time duration of MC-CDMA method which has studied for next-generation high-speed data transmission is not sufficiently large compared to delay spread of channel, the performance is degraded by generation of intersymbol interference. In this paper, this problem will solve through serial to parallel convertor and make large sufficiently time duration of signal compared to delay spread of channel and rise variable spectral efficiency through the number of serial to parallel convertor subchannel we will add to parallel frequency diversity block for improve the performance in mobile Communication. Spectral efficiency of the proposed system is counted and compared to spectral efficiency of MC-CDMA and investigated through computer simulations by using multipath Rayleigh fading channel.

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Prevalence and Intensity of Clonorchis sinensis Metacercariae in Freshwater Fish from Wicheon Stream in Gunwi-gun, Gyeongsangbuk-do, Korea

  • Sohn, Woon-Mok;Na, Byoung-Kuk;Cho, Shin-Hyeong;Ju, Jung-Won;Son, Dong-Chul
    • Parasites, Hosts and Diseases
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    • v.56 no.1
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    • pp.41-48
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    • 2018
  • The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.

Effects of McKenzie Exercise on the Neck Muscles Fatigue, and Neck Disability Index in Chronic Neck Pain Patients (맥켄지운동이 만성 목통증 환자의 목주위 근육 피로도와 목 장애지수에 미치는 영향)

  • Kang, Jeong-Il;Baek, Seung-Yun;Jeong, Dae-Keun
    • Journal of the Korean Society of Physical Medicine
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    • v.14 no.4
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    • pp.93-101
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    • 2019
  • PURPOSE: This study tries attempted to provide basic clinical data to reduce pain and improve function by comparing the muscle fatigue of the superficial neck muscles and neck disability index (NDI) by performing McKenzie exercise or passive stretching exercise for chronic neck pain patients. METHODS: Sixteen chronic neck pain patients were selected and divided into the McKenzie group (n=8) and passive stretching group (n=8). The intervention program was performed three times a week for four weeks. The time for one exercise was 30 minutes. Before the intervention, the muscle fatigue the superficial neck muscles and NDI were measured. They were measured again after four weeks using the same method. RESULTS: The median frequency of the superficial neck muscles increased significantly in the McKenzie group and passive stretching group (p<.05). The NDI of both the McKenzie group and the passive stretching group decreased significantly. A comparison of the groups, revealed a significant difference in only the median frequency values of the upper trapezius muscle and splenius capitis muscle (p<.05). The NDI values of both groups were similar. CONCLUSION: Both McKenzie exercise and passive stretching exercises showed a significant difference in the degree of fatigue and NDI. McKenzie exercise delayed the replace of the fast twitch fibers which helped improve the muscle fatigue of the upper trapezius muscle and splenius capitis muscle. On the other hand, additional studies applying more variables for the muscle function to improve the symptom of chronic neck pain patients will be needed.