• Title/Summary/Keyword: cut-off effect

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Filtering for reducing aliasing effects on auto-multiscopic monitor (무안경식 입체 다시점 모니터의 엘리어싱 감소를 위한 필터링 기법)

  • Park, Myung-Su;Yoo, Ji-Sang
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.591-599
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    • 2010
  • In this paper, we propose a disparity-adaptive filtering method to reduce view-aliasing and inter-perspective aliasing on auto-multiscopic 3D display. View aliasing by the subsampled multi-view images could happen if the resolution of an auto-multiscopic monitor is lower than that of the original multi-view images. Furthermore, multi-view images on auto-multiscopic monitor usually cause eye strain and fatigue because of inter-perspective aliasing by discontinuity that exists between viewpoints. The greater disparity value becomes, the stronger these types of aliasing could be. Thus, we design a lowpass filter whose cut-off frequency is determined adaptively to the number of intermediate reconstructed views and their disparity's strength. Though experimental results, we show that the proposed filtering algorithm could reduce the aliasing effect very efficiently by using DSCQS (double stimulus continuous quality scale method).

Comparison of the effect of hand instruments, an ultrasonic scaler, and an erbium-doped yttrium aluminium garnet laser on root surface roughness of teeth with periodontitis: a profilometer study

  • Amid, Reza;Kadkhodazadeh, Mahdi;Fekrazad, Reza;Hajizadeh, Farzin;Ghafoori, Arash
    • Journal of Periodontal and Implant Science
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    • v.43 no.2
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    • pp.101-105
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    • 2013
  • Purpose: The present study aimed to measure root surface roughness in teeth with periodontitis by a profilometer following root planning with ultrasonic and hand instruments with and without erbium-doped yttrium aluminium garnet (Er:YAG) laser irradiation. Methods: Sixty single-rooted maxillary and mandibular teeth, extracted because of periodontal disease, were collected. The crowns and apices of the roots were cut off using a diamond bur and water coolant. The specimens were mounted in an acrylic resin block such that a plain root surface was accessible. After primary evaluation and setting a baseline, the samples were divided into 4 groups. In group 1, the samples were root planned using a manual curette. The group 2 samples were prepared with an ultrasonic scaler. In group 3, after scaling with hand instrumentation, the roots were treated with a Smart 1240D plus Er:YAG laser and in group 4, the roots were prepared with ultrasonic scaler and subsequently treated with an Er:YAG laser. Root surface roughness was then measured by a profilometer (MahrSurf M300+RD18C system) under controlled laboratory conditions at a temperature of $25^{\circ}C$ and 41% humidity. The data were analyzed statistically using analysis of variance and a t-test (P<0.05). Results: Significant differences were detected in terms of surface roughness and surface distortion before and after treatment. The average reduction of the surface roughness after treatment in groups 1, 2, 3, and 4 was 1.89, 1.88, 1.40, and 1.52, respectively. These findings revealed no significant differences among the four groups. Conclusions: An Er:YAG laser as an adjunct to traditional scaling and root planning reduces root surface roughness. However, the surface ultrastructure is more irregular than when using conventional methods.

A Short Wavelength Filter Based on Dissimilar Dispersive Property Between a Thermally Expanded Cored Fiber and an External Medium (측면 연마된 열확산 코어 광섬유와 외부 물질의 분산 특성 차이를 이용한 단파장 통과 필터)

  • Kim, Kwang-Taek;Lee, Kyu-Hyo;Shin, Eun-Soo;Hwangbo, Seung;Sohn, Kyung-Rak;Kim, Jeong-Geun;Lee, Dong-Ho;Song, Jae-Won
    • Korean Journal of Optics and Photonics
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    • v.16 no.6
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    • pp.494-499
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    • 2005
  • We have demonstrated a fiber short-wavelength filter with a good cut-off property using dissimilar dispersive properties between? a thermally expanded cored fiber and an external medium. Side-polishing is applied to coupling between the fiber and the external medium. The experimental results revealed that the bend edge wavelength can be adjusted by controlling the degree of core expansion. Futhermore, the sharpness of wavelength response? was significantly? improved by employing expanded core fiber instead of a conventional single mode fiber. Tuning range of the band edge wavelength exceeded 400 m based on thermo-optic effect of the external medium.

A Study on Real IP Traceback and Forensic Data Generation against Bypass Attack (우회적인 공격에 대한 실제 IP 역추적 실시와 포렌식 자료 생성)

  • Youn, Byung-Sun;Yang, Hae-Sool;Kim, Dong-Jhoon
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.1
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    • pp.143-151
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    • 2008
  • Execute IP traceback at this paper as target an intruder's attacking that Bypass Attack in order to avoid an exposure of own Real IP address Design IP traceback server and agent module, and install in Internet network system for Real IP traceback. Set up detection and chase range aggressive loop around connection arbitrariness, and attack in practice, and generate Real IP data cut off by fatal attacks after data and intrusion detection accessed general IP, and store to DB. Generate the Forensic data which Real IP confirms substance by Whois service, and ensured integrity and the reliability that buy to early legal proof data, and was devoted to of an invader Present the cyber criminal preventive effect that is dysfunction of Ubiquitous Information Society and an effective Real IP traceback system, and ensure a Forensic data generation basis regarding a judge's robe penalty through this paper study.

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Ultrafiltration Treatment for Car Washing Effluent (한외여과막을 이용한 자동차 세척배수의 처리)

  • 장규만
    • Membrane Journal
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    • v.9 no.4
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    • pp.202-208
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    • 1999
  • The car washing effluent containing various oils and detergent was treated by ultrafiltration membranes. Dead-end type stirred cell (Amicon 8050) with 10, 30 and lOOk dalton membranes was used to determine permeation and rejection characteristics for the car washing effluent. In case of low molecular weight cut-off membranes, the effect of membrane fouling was weak under the applied pressures. However, the permeation flux for YM100 membrane(look dalton) may be affected by oil layer formation on the membrane surface as well as oil particle plugging for a part of membrane pores due to compressible and deformable oil properties. Oil and particle rejections in the permeates were over 95%, but detergent was passed easily through the membranes. Hence, the permeates containing detergent can be recycled to the system, and may reduce water pollution. Also, the car washing effluent was treated continuously by a capillary type ultrafiltration membrane of MWCO 50k dalton. The experimental data were fitted suitably to the cake filtration model.

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A Robust PLL of PCS for Fuel Cell System under Unbalanced Grid Voltages (불평형 계통전압에 강인한 연료전지용 전력변환시스템의 PLL 방법)

  • Kim, Yun-Hyun;Kim, Wang-Rae;Lim, Chang-Jin;Kim, Kwang-Seob;Kwon, Byung-Ki;Choi, Chang-Ho
    • Proceedings of the KIPE Conference
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    • 2008.06a
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    • pp.103-105
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    • 2008
  • In grid-interconnection system, a fast, robust and precise phase angle detector is most important to grid synchronization and the active power control. The phase angle can be easily estimated by synchronous dq PLL system. On the other hand under unbalanced voltage condition, synchronous dq PLL system has problem that harmonics occur to phase angle or magnitude of grid voltage because of the effect of the negative sequence components. So, To eliminate the negative sequence components, the PLL method using APF (All Pass Filter) in a stationery reference frame to extract positive sequence components under unbalanced voltage condition is researched. In this paper, we propose a new PLL method with decoupling network using APF in a synchronous reference frame to extract the positive sequence components of the grid voltage under unbalanced grid. The cut-off frequency of APF in a synchronous reference frame can be set to twice of the fundamental frequency comparing with that of APF in a stationery reference frame which is the fundamental frequency. The proposed PLL strategy can detect the phase angle quickly and accurately under unbalanced gird voltages. Simulation and experimental results are presented to verify the proposed strategy under different kind of voltage dips.

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The Effect of n-Alkanols on the Lateral Diffusion of Synaptosomal Plasma Membrane Vesicles Isolated from Bovine Cerebral Cortex (n-Alkanols가 소의 대뇌피질로부터 분리한 Synaptosomal Plasma Membrane Vesicles의 측방확산운동 범위와 속도에 미치는 영향)

  • Chung, In-Kyo;Kang, Jung-Sook;Yun, Il
    • The Korean Journal of Pharmacology
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    • v.29 no.1
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    • pp.157-163
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    • 1993
  • Intramolecular excimer formation with the fluorescent probe 1,3-di(1-pyrenyl)propane (Py-3-Py) was used to investigate the effects of methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol and 1-decanol on the lateral diffusion of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV). The n-alkanols increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMV. In a dose-dependent manner, n-alkanols increased lateral diffusion of hydrocarbon region of bulk (inner+outer monolayers) SPMV lipid bilayers, and the potencies of n-alkanols up to l-nonanol increased with carbon chain length. It appears that the potencies in bilayer fluidization due to the lateral diffusion increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity.

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Modified deep sedation with halothane and midazolam for the definitely negative behavior pediatric patient. (행동조절이 어려운 소아치과 환자 치료시 Halothane과 Midazolam을 사용한 Modified Deep Sedation)

  • Yoon, Hyung-Bae
    • Journal of the korean academy of Pediatric Dentistry
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    • v.25 no.1
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    • pp.38-46
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    • 1998
  • Management of children who show negative response to treatment was difficult. Usually the dentist used the restraintor sedatives for these children. Especially it is very difficult to management of definitely negative behavior patients who resist to ordinary sedative technics including psychosedation and various sedatives. These patients were managed with general anesthesia. Midazolam was used for sedation of non-cooperative pediatric patients and halothane for induce initial sleepness, If the patient shows negative response to management after 15 minutes of midazolam administration, used the halothane in 30 to 120 seconds for calm down the patient. After induce sleepness, cut off the halothane administration and maintain the sedation with $N_2O$ in 50-70 vol.% concentration. This technic reduce the toxity and untoward effects of major anesthetics. To compare the difference of sedation effect by dosage, dose of 0.2mg/kg and 0.3mg/kg were injected respectively. Though there's no statistical difference in duration and results between two dosage but show the increment of score with age, If the patients show positive response to management after midazolam administered. try to conscious sedation with nitrous oxide in 30 to 70 vo.% concentration. Nitrous oxide concentration was administered slowly according to their consciousness and response to treatment by increment or decrement. The success rate of conscious sedation were 21.2% in 0.2mg/kg and 30.3% in 0.3mg/kg. There's many factors in proceed of conscious sedation. The most important factors are age of patient and experience of children for dental care.

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A Study on The Safety Management of City Gas Pipelines Attached on the Bridges (교량에 설치된 도시가스배관의 안전관리에 관한 연구)

  • Yun, Young-Man;Son, Sang-Geun;Choi, Do-Kyun;Lee, Su-Kyung
    • Journal of the Korean Institute of Gas
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    • v.22 no.1
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    • pp.45-52
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    • 2018
  • In this study, 398 city gas pipe systems installed on the bridges were surveyed and analyzed classified characteristics about the ages, length, and remote isolation devices installed or not. As a result of analysis, 43.0% pipes have been used more than 20 years and 89.4% do not have remote cut-off devices, so this study suggest safety management ways for the issues. Chosen 76 pipes were researched stress strain characteristics by CAESAR-II which is a specialized program for stress analysis. And, when a loop is installed on the bridge pipe, effect on code stress by the location and size of the loop was performed. This study can help to improve safety level by revising criteria of new installation, inspection and diagnostic.

High definition VOD contents management system design of H.264 basis (H.264기반의 고화질 VOD 콘텐츠관리시스템(CMS) 설계)

  • Min, Byoung-won;Oh, Yong-sun;Lee, Jung-man
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.465-468
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    • 2008
  • Recently, VOD market is getting increased and most of public, educational organization, enterprises are providing service as content managing system of WMV standard subordinated to Window OS of Microsoft company. VOD CMS of WMV standard have problem that frequent cut-off, small-size of screen, and image quality which is also chronic problem. In order to solve this problem, technology solving the problem has developed through minimization of buffering time, screen size, high quality sound, and high quality image by image codec and streaming engine which is H. 264. But there are still a problem that systematic management of contents or distribution is difficult. This study expected that there would be a effect preoccupying significant stand of world wide H.264 high quality image mobile VOD managing market by securing domestic on-line VOD contents integrated managing technology by designing system for image VOD contents management having a limit in wmv market and combining H.264 which is new technology.

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