• Title/Summary/Keyword: Reverse calculation

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Hull Deflections Affecting on the Ship's Propulsion Shafting Alignment in 46K Oil/Chemical Carrier

  • Lee, Yong-Jin;Kim, Ue-Kan;Kim, Jong-Su
    • Journal of Advanced Marine Engineering and Technology
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    • v.30 no.7
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    • pp.800-807
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    • 2006
  • This paper introduces the hull deflection analysis method by using the direct measurements. Accordingly, this paper demonstrates how the hull deflection data is obtained by the reverse calculations using the bending moments from the stain gauge and bearing reactions from jack-up method. Where the hull deflection data provided by this research is used for the shafting alignment calculations for identical or similar vessels, shafting failures due to hull deflections can be minimized. It will also save time and expenses associated finite element method to predict hull deflections.

A Study on 1 kW Development of Reverse Brayton Cycle Cryocooler System (1 kW급 역브레이튼 극저온 냉동기 개발에 관한 연구)

  • 권용하;박재홍;정종환;김영수
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2003.10a
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    • pp.176-180
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    • 2003
  • To obtain superconducting state, a reliable cryocooler system is required. Structural and thermal design have been performed to design cryocooler system operated with reverse Brayton cycle using gas neon as refrigerant. This cryocooler system consists of compressor recuperator, coldbox, control valves and has 1 ㎾ cooling capacity. Heat loss calculation was conducted for the given cryocooler system by considering the conduction and radiation through the multi-layer insulation (MLI) and high vacuum. The results can be summarized as; conduction heat loss is 7 W in valves and access port and radiation heat loss is 18 W through the surface of cryocooler. The full design specifications were discussed.

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Calculation of Stretched Laminar Diffusion Flame Using the Coherent Flame Sheet Model (코히어런트 화염면 모델을 이용한 스트레치 층류 확산 화염의 수치 계산)

  • 정진은;진영욱
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.1
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    • pp.17-22
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    • 2000
  • The transient process simplified by the 1-D stretched laminar flame formed at the fuel-oxidizer interface was investigated using the coherent flame sheet model. Under the combustion environment of high temperatures and pressures the results show that the time required to reach the steady state was relatively short compared to the reverse of strain rate. Hence the employment of the tabulation of precalculated steady-flame results in the calculation of turbulent diffusion flames using the coherent flame sheet model is concluded valid, Also upstream temperatures were found to have only a minor effect on the nondimensional flame temperature and nondimensional fuel even through the letter is sensitive to pressure changes.

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Educational Simulator for Transmission Network Use of System Charge (송전망 이용요금산정을 위한 교육용 시뮬레이터 개발)

  • Kim, H.H.;Song, H.Y.;Lee, C.J.;Park, J.B.;Shin, J.R.
    • Proceedings of the KIEE Conference
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    • 2006.11a
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    • pp.201-203
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    • 2006
  • This paper presents a graphical windows-based software for the education and training of the transmission network use of system charge. The developed simulator consist of the main module(MMI,GUI), the power flow module(PF), the power flow tracing module(PFT) and management of usage cost DB module(UCD). Each module has a separate graphical and interactive interfacing window. To have effective education for transmission network use of system charge, the developed simulator are provided with two power system analysis methods. Input data of power system can use the format of PSS/E input data. Also calculation of power flow tracing are provided with four methods such as "Felix Wu","Modified Felix Wu", "DCLF ICRP" and "Reverse MW mile". Results of calculation for usage cost are shown on the window through the table or chart. Therefore user can confirm the detailed differences of results from each calculation method.

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Accuracy Analysis of GPS-derived Precipitable Water Vapor According to Interpolation Methods of Meteorological Data (기상자료 보간 방법에 의한 GPS기반 가강수량 산출 정확도 분석)

  • Kim, Du-Sik;Won, Ji-Hye;Kim, Hye-In;Kim, Kyeong-Hui;Park, Kwan-Dong
    • Spatial Information Research
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    • v.18 no.4
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    • pp.33-41
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    • 2010
  • Approximately 100 permanent GPS stations are currently operational in Korea. However, only 10 sites have their own weather sensors connected directly to the GPS receiver. Thus. calculation of meteorological data through interpolation of AWS data are needed to determine precipitable water vapors at a specific GPS station without a meteorological sensor. This study analyzed the accuracy of two meteorological data interpolation methods called reverse sea level correction and kriging. As a result, the root-mean square-error of reverse sea level correction were seven times more accurate in pressure and twice more accurate in temperature than the kriging method. For the analysis of PWV accuracy, we calculated GPS PWV during the summer season in :2008 by using GPS observation data and interpolated meteorological data by reverse sea level correction. And, we compared GPS PWV s based on interpolated meteorological data with those from radiosonde observations and GPS PWV s based on onsite GPS meteorological sensor measurements. As a result, the accuracy of GPS PWV s from our interpolated meteorological data was within the required operational accuracy of 3mm.

Biochemical and structural comparisons of non-nucleoside reverse transcriptase inhibitors against feline and human immunodeficiency viruses

  • Siriluk Rattanabunyong ;Khuanjarat Choengpanya;Chonticha Suwattanasophon ;Duangnapa Kiriwan ;Peter Wolschann ;Thomanai Lamtha ;Abdul Rajjak Shaikh ;Jatuporn Rattanasrisomporn;Kiattawee Choowongkomon
    • Journal of Veterinary Science
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    • v.24 no.5
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    • pp.67.1-67.15
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    • 2023
  • Background: Feline immunodeficiency virus (FIV) causes an acquired immunodeficiency-like syndrome in cats. FIV is latent. No effective treatment has been developed for treatment the infected cats. The first and second generations non-nucleoside reverse transcriptase inhibitors (NNRTIs) for HIV treatment, nevirapine (NVP) and efavirenz (EFV), and rilpivirine (RPV), were used to investigate the potential of NNRTIs for treatment of FIV infection. Objective: This study aims to use experimental and in silico approaches to investigate the potential of NNRTIs, NVP, EFV, and RPV, for inhibition of FIV reverse transcriptase (FIV-RT). Methods: The FIV-RT and human immunodeficiency virus reverse transcriptase (HIV-RT) were expressed and purified using chromatography approaches. The purified proteins were used to determine the IC50 values with NVP, EFV, and RPV. Surface plasmon resonance (SPR) analysis was used to calculate the binding affinities of NNRTIs to HIV-RT and FIV-RT. The molecular docking and molecular dynamic simulations were used to demonstrate the mechanism of FIV-RT and HIV-RT with first and second generation NNRTI complexes. Results: The IC50 values of NNRTIs NVP, EFV, and RPV against FIV-RT were in comparable ranges to HIV-RT. The SPR analysis showed that NVP, EFV, and RPV could bind to both enzymes. Computational calculation also supports that these NNRTIs can bind with both FIV-RT and HIV-RT. Conclusions: Our results suggest the first and second generation NNRTIs (NVP, EFV, and RPV) could inhibit both FIV-RT and HIV-RT.

Context Based Real-time Korean Writing Correction for Foreigners (외국인 학습자를 위한 문맥 기반 실시간 국어 문장 교정)

  • Park, Young-Keun;Kim, Jae-Min;Lee, Seong-Dong;Lee, Hyun Ah
    • Journal of KIISE
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    • v.44 no.10
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    • pp.1087-1093
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    • 2017
  • Educating foreigners in Korean language is attracting increasing attention with the growing number of foreigners who want to learn Korean or want to reside in Korea. Existing spell checkers mostly focus on native Korean speakers, so they are inappropriate for foreigners. In this paper, we propose a correction method for the Korean language that reflects the contextual characteristics of Korean and writing characteristics of foreigners. Our method can extract frequently used expressions by Koreans by constructing syllable reverse-index for eojeol bi-gram extracted from corpus as correction candidates, and generate ranked Korean corrections for foreigners with upgraded edit distance calculation. Our system provides a user interface based on keyboard hooking, so a user can easily use the correction system along with other applications. Our system improves the detection rate for foreign language users by about 45% compared to other systems in foreign language writing environments. This will help foreign users to judge and correct their own writing errors.

Automobile Collision Reconstruction Using Post-Impact Velocities and Crush Profile (충돌 후 속도와 충돌 변형으로부터 자동차 충돌 재구성)

  • 한인환
    • Journal of Korean Society of Transportation
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    • v.18 no.4
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    • pp.107-115
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    • 2000
  • We suggest a method which solves the planar, two vehicle collision reconstruction problem. The method based on the Principle of impulse and momentum determines the pre-impact velocity components from Post-impact velocity components, vehicle Physical data and collision geometry. A novel feature is that although the impact coefficients such as the restitution coefficient and the impulse ratio are unknown, the method can estimate automatically the coefficients and calculate the pre-impact velocity components. This reverse calculation is important for vehicle accident reconstruction, since the pre-impact velocities are unknown and Post-impact Phase is the starting Point in a usual collision analysis. However. an inverse solution is not always Possible with the analytical rigid-body impact model. Mathematically, one does not exist under the common velocity condition. On the other hand, our method has a capability of reverse calculation under the condition if the absorbed energy during the collision process can be estimated using the crush profile. To validate the developed collision reconstruction a1gorithm, we use car-to-car collision test results. The analysis and experimental results agree well in the impact coefficients and the Pre-impact velocity components.

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Reverse Link Interference Bounds in CDMA Cellular Systems (CDMA 셀룰라 시스템에서의 역방향 간섭 한계)

  • 김호준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.3
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    • pp.395-402
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    • 2003
  • The capacity of a CDMA cellular system is determined by the amount of interference, therefore the exact estimation of interference is important to evaluate the system performance. In this paper, we propose an approximated equation which calculates reverse link other cell interference in the CDMA cellular systems. The equation using Riemann-Zeta function has a property that it is useful in case of any radio propagation loss exponents. And we compare calculation results with simulation results in other to verify it's usefulness. The upper bound of system capacity calculated with the proposed approximated equation gives almost alike result with the simulation. The proposed interference bound is useful to calculate system capacity and to evaluate some algorithm in a hierarchical cellular system which must be considered various propagation exponents.

Effects of Non-Uniform Traffic Distribution on the Capacity of Reverse Link CDMA System

  • Cho, Choon-Geun;Ann, Jong-Hoon;Tchah, Kyun-Hyon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.12A
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    • pp.1828-1835
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    • 2000
  • In this paper, we analyzed the other-cell interference characteristics for various non-uniform traffic distributions and their effects on the capacity of multi-cell CDMA system. We consider three different traffic distributions, i.e., linear, exponential and Gaussian traffic distribution with distribution parameters. Changing the distribution parameter, we can obtain the center-focused distributions or uniform distributions for each model. From the results of other-cell interference calculation we can see that the other-cell interference decreases, as the user concentrates on the base station. Also using frequency reuse efficiency indicating the capacity reduction of a multi-cell system when compared to a single cell system, we evaluate the effect of traffic distribution on the reverse link CDMA capacity. For linear case, the capacity of multi-cell system is reduced to 0.637∼0.867 times that of single cell system. On the other hand, for both exponential and Gaussian cases, the capacity under a multi-cell environment is equal to 70∼100% of that under a single cell. Therefore, we conclude that the average capacity of multi-cell CDMA system are increased when users are likely to be at near the cell base station due to reduced total other-cell interference and decreased when users exist at near the cell edge regardless of traffic distribution models.

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