• Title/Summary/Keyword: Bench

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IPTV QoE improvement on FTTH internet (FTTH 광인터넷에서 IPTV 체감품질 개선)

  • Kwon, Jeong-Gook;You, Jae-Hoon;Kim, Bong-Tae;Park, Chun-Kwan;Lee, Sang-Ho
    • Journal of KIISE:Information Networking
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    • v.34 no.6
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    • pp.525-532
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    • 2007
  • Recently, broadband access networks have been competitively deployed all over the world with the development of various multimedia services for such a network. ETRI(Electronics and Telecommunications Research Institute) built the FTTH(Fiber-to-the-Home) service center to develop a next-generation equipment and a high-quality service/platform as well as to promote domestic industry in the field of optical communication. The FTTH service center has a variety of test equipments such as FTTH standard testbed for a BMT(Bench Mark Test), a network operation center, and IPTV service equipments. Also, ETRI deployed a new type of commercial optical access networks cooperating with ISP(Internet service provider). In this paper, we analyzed the quality degradation appeared in QoE(Quality of Experience), when IP data broadcasted from the FTTH service center is transmitted to subscribers through the commercial optical access network. Moreover, we proposed a noble solution to address this problem.

BMT-Model Based Evaluation of Power Consumption of Mobile Context-Aware Application (BMT 모델 기반 모바일 상황인지 어플리케이션의 전력 소비 평가)

  • Jeon, Jaehong;Baek, Dusan;Kim, Kyung-Ah;Lee, Jung-Won
    • KIPS Transactions on Computer and Communication Systems
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    • v.5 no.11
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    • pp.411-418
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    • 2016
  • Context-aware application has a lot of power consumption because it creates context by using a number of smartphone's sensors. Furthermore, only few kinds of researches have been conducted that provide information for the evaluation result of power consumption in the aspect of applications. In addition, evaluation of power consumption do not consider user's usage pattern or provide only total amount of power consumption, and inform developers power consumption of sensors undistinguishable. It makes developers hard to develop a power consumption-considered application. If developers could get information for power consumption of context-aware application in detail, a development of power-considered context-aware applications would be possible. Consequently, this paper proposes a BMT(Bench Mark Test) model which is able to inform developers useful evaluation criteria and result about power consumption of smartphone's components and sensors with usage pattern considered.

A Study on Lubrication Characteristics of Automotive Engine Oil Merchandised in Domestic (국내 판매되는 자동차용 엔진오일의 윤활특성 연구)

  • Kim, Shin;Kang, Hyung-Kyu;Lim, Tae-Yoon;Kwon, Jong-Soo;Kim, Jai-Gueon;Choi, Dae-Sung;Kim, Dong-Kil;Jung, Choong-Sub
    • Tribology and Lubricants
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    • v.25 no.6
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    • pp.432-437
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    • 2009
  • The effect of oxidation in SAE 5W30 engine oils on friction and wear characteristics was investigated using reciprocating bench tester and shell 4-ball tester. Commercial engine oils were collected and oxidized using the KS M 2021 method modifying the oxidation time. Kinematic viscosity, total acid number(TAN), FT-IR spectrum and total base number(TBN) also measured to examine the chemical change of oils with oxidation. The results showed that TAN was slightly changed and Kinematic viscosity was suddenly increased during the oxidation stage. however, TBN results keep a constant slope after TBN linearly decreased with oxidation time. Spectroscopy results showed that spectrums were orderly increased at $1710cm^{-1}$ during the oxidation time. Friction test results showed that oxidation of oils formed unstable friction layers causing higher fluctuating friction. however, the wear resistance was independent of oxidized time due to the different friction characteristics by oxidation. We found several factors in relation to lubrication properties with oxidation time. This factors were Viscosity, TBN, change of FT-IR spectrum, friction coefficient using reciprocating bench tester and wear scar.

Preparation of PVDF Hollow Fiber Membrane and Absorption of SO2 from Flue Gas Using Bench Scale Gas-Liquid Contactor (PVDF 중공사막 제조 및 벤치규모 기-액 접촉기를 이용한 SO2 흡수특성)

  • Park, Hyun-Hee;Jo, Hang-Dae;Kim, In-Won;Lee, Hyung-Keun
    • Korean Chemical Engineering Research
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    • v.46 no.3
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    • pp.521-528
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    • 2008
  • The micro-porous asymmetric PVDF hollow fiber membranes for gas-liquid contactor were prepared by the dry-jet wet phase inversion process and the characteristics of hollow fiber membranes were evaluated by the gas permeation method and scanning electron microscope. The chemical absorbent for removal of $SO_2$ gas was sodium hydroxide at bench scale hollow fiber membrane contactor. The experiments were performed in a counter-current mode of operation with gas in the shell side and liquid in the fiber lumen of the module to examine the effect of various operating variables such as concentration of absorbent, gas flow rate, L/G ratio and concentration of inlet $SO_2$ gas on the $SO_2$ removal efficiency using PVDF hollow fiber membrane contactor. Membrane mass transfer coefficient($k_m$) was calculated by mathematical modeling. The volumetric overall mass transfer coefficient increased with increasing the concentration of absorbent and L/G ratio. The increase of the absorbent concentration and L/G ratio not only provides more sufficient alkalinity but also decreases liquid phase resistance. The volumetric overall mass transfer coefficient increased with increasing gas flow rate due to decreasing the gas phase resistance.

Tolerance design of position accuracy of optical components for micro optical system (마이크로 광 시스템 구현을 위한 광학 부품의 위치 정밀도 허용오차 설계)

  • 이재영;황병철;박헌용;박세근;이승걸;오범환;이일항;최두선
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.7
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    • pp.13-20
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    • 2004
  • In order to set up the design of micro optical bench, optical coupling efficiencies of two sets of test benches are calculated. Simple linear connections of incoming and outgoing optical fibers with and without ball lenses are designed. Positional errors that are possible in actual fabrication processes we considered in the calculations and their tolerances are determined from -3 ㏈ conditions. For a simple fiber-to-fiber connection, the lateral misalignment should be limited to 2.7 um and tilt error 5.8o. In case of the fiber-to-fiber with ball lens, the working distance between fibers can be extended over 60 um. The optical coupling efficiency depends strongly on the positional errors of ball lenses along the optical axis, and it is also found that the lateral and vertical positional errors should be considered simultaneously in order to keep the high coupling efficiency.

Assessment of Performance of Motor System for City Bus (노선버스용 구동모터 시스템의 성능평가)

  • Lee, Yoon-Ki;Myong, Kwang-Jae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.2
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    • pp.189-196
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    • 2011
  • Recently, research and development of a hybrid system for passenger cars as well as for heavy-duty vehicles has become more intensive. An electric powertrain system using an electric motor can replace conventional gasoline and diesel engines. The electric motor has a higher efficiency, better acceleration performance, and is more comfortable than conventional powertrain systems; however, new methods for assessing power performance and energy convergence efficiency have to be investigated because the characteristics of an electric motor are entirely different from those of an internal combustion engine (ICE). In this study, an experiment was carried out on a motor (PMSM: Permanent Magnet Synchronous Motor) test bench. One simple driving mode and four other driving modes identified from real-world driving data of a city bus were selected to perform the experiment on the motor test bench. Then, methods for assessing the acceleration performance, energy convergence efficiency, regenerative effect, etc., were investigated. It was found that the energy efficiency of PMSM was about 90% and that 40% of demand energy was regenerated.

Analysis of Ethernet Wwitch Measurement Uncertainty for KOLAS Testing Laboratory Accreditation (KOLAS 공인시험기관 인정을 위한 이더넷 스위치의 측정불확도 분석)

  • Lee, Jae-Jeong;Ryu, Han-Yand;Nam, Ki-Dong;Kim, Chang-Bong
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.12
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    • pp.1-8
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    • 2011
  • Actively in progress in the field of general industrial KOLAS (Korea Laboratory Accreditation Scheme) accreditation test the switch, router, network equipment, such as accreditation status in the field can not be found. Company's self-tsting or BMT (Bench Marking Test) through the evaluation process for network equipment, but the test reports issued by accredited laboratories with quality differences. Requested by public institutions or other providers of accredited test reports increasing demand for network equipment in Korea accredited testing laboratory shall be made as soon as possible. In this paper, as required by KOLAS in the field of network equipment testing laboratory accreditation program in the process acquired through the analysis of measurement uncertainty and, to propose effective direction.

Comparison of GPS/Levelling Geoid with PNU95 Geoid in Cheju Island (제주도의 GPS/Levelling 지오이드와 PNU95 지오이드)

  • Choi, Kwang-Sun;Park, Je-Hui;Hong, Sun-Hun
    • Journal of the Korean Geophysical Society
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    • v.3 no.1
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    • pp.13-24
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    • 2000
  • In this study, GPS surveying at bench marks in Cheju Island and with these data, calculate GPS/Levelling geoid in Cheju area. And compare this geoid with PNU95 Geoid. The results are as follows : 1. The ellipsoidal height of each bench mark was measured ${\pm}3cm$ with accuracy in GPS surveying. 2. Calculated CPS/Levelling Geoid well represents the variations of Cheju terrain. The correlation formula between the geoid and elevation above sea level in Cheju area is as fellow : $$N\;=\;0.001082\;{\times}\;h\;+\;25.458\;{\pm}\;0.227\;s.d.$$ 3. Calculated GPS/Levelling Geoid and PNU95 Geoid are welt fitted and the RMS difference between the two Geoids is 0.14 m.

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A Study on the Improvement of Surface Blasting Method in Pasir Coal Mine (파시르 탄광에서의 채탄발파공법에 대한 문제점 분석 및 개선방안 연구)

  • Choi Byung-Hee;Ryu Dong-Woo;SunWoo Choon
    • Explosives and Blasting
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    • v.24 no.1
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    • pp.57-62
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    • 2006
  • The typical blasting method adopted in Pasir Coal Mine is a surface blasting technique with a single free face. It means that there is only one free face, which is usually the ground surface. This kind of blasting method is easy to use but inevitably causes enormous ground vibrations, which, in turn, can affect the stability of the slopes comprising the various boundaries of the open pit mine. In addition, the method also has the problem of lowering the blast efficiency compared to other methods such as bench blasting methods or ones with more than two free faces. In this respect, a project was launched to develop a new blasting method that is suitable for controling the ground vibration and enhancing the blast efficiency. As a part of the project, authors investigated the current blasting method as well as the overall pit developing process in the mine, and established some important guidelines that should be observed during the whole development process. This paper presents the details of the typical blasting pattern and the pit developing method in the mine, and suggests the guidelines determined from the results of the observations.

A Study on the Material of Furniture in Goryeo (고려시대 가구재료 연구)

  • Cho, Sook-Kyung
    • Journal of the Korea Furniture Society
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    • v.25 no.1
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    • pp.19-27
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    • 2014
  • This paper studied the materials of the furniture which the noble men used in Goryeo, based on the furniture material category of solid wood furniture, lacquerware inlaid with mother-of-pearl and hardware. As for the solid wood furniture, the wood and furniture types are inferred based on the documents. The trees used for the wood furniture were zelkova, korean willow, pine, royal paulownia, maidenhair tree, korean pine, chinese juniper and elm. The furniture types were table, chair, wooden bench, small portable table, writing table, and folding screen. As to the types of lacquerware inlaid with mother-of-pearl, most of them were hams with top, which were made of abalone shells. The features of the lacquerware inlaid with mother-of-pearl were in detail and elaborate like the pattern of the full bloomed chrysanthemum. Writing tables were also made of lacquerware as pieces of furniture. Distinctively, the mother-of-pearl furniture material was popular enough to be used even in a horse saddle. Regarding the metal feldspar used as both a practical use and decoration, there are drop handle, hinge, the front basis, and lock seen in the artifacts, which were made of cast iron, bronze, and brass. Their manufacture techniques were eojamoon, bratticing and sheet metal. Through this study of the furniture materials used in Goryeo, it seems that Goryeo furniture focused on the functions rather than on the decorations, and in turn the forms were simple and basic. The technique of mother-of-pearl, a bit elaborate one, was used in the props furniture like kitchen wares, hams, or writing talbes. Probably, the solid wood is inferred to be used in a low wooden bench, a chair, and a table based on the documents.

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