• 제목/요약/키워드: method of research

검색결과 66,252건 처리시간 0.081초

A new decision method for construction scheme of shallow buried subway station

  • Qiu, Daohong;Yu, Yuehao;Xue, Yiguo;Su, Maoxin;Zhou, Binghua;Gong, Huimin;Bai, Chenghao;Fu, Kang
    • Geomechanics and Engineering
    • /
    • 제30권3호
    • /
    • pp.313-324
    • /
    • 2022
  • With the development of the economy, people's utilization of underground space are also improved, and a large number of cities have begun to build subways to relieve traffic pressure. The choice of subway station construction method is crucial. If an inappropriate construction method is selected, it will not only waste costs but also cause excessive deformation that may also threaten construction safety. In this paper, a subway station construction scheme selects model based on the AHP-fuzzy comprehensive evaluation. The rationality of the model is verified using numerical simulation and monitoring measurement data. Firstly, considering the economy and safety, a comprehensive evaluation system is established by selecting several indicators. Then, the analytic hierarchy process is used to determine the weight of the evaluation index, and the dimensionless membership in the fuzzy comprehensive evaluation method is used to evaluate the advantages and disadvantages of the construction method. Finally, the method is applied to Liaoyang east road station of Qingdao metro Line 2, and the results are verified by numerical simulation and monitoring measurement data. The results show that the model is scientific, practical and applicable.

가변 자유수면 패널법을 이용한 선체 주위 포텐셜 유동 해석 (Variable Free Surface Panel Method for Potential Flow Analysis around a Ship)

  • 최희종;김진;반석호;박일룡;김광수
    • 대한조선학회논문집
    • /
    • 제45권1호
    • /
    • pp.54-62
    • /
    • 2008
  • A new solution method was developed to solve the free surface flow around a hull and named as 'Variable Free Surface Panel Method'. In the method the non-linearity of the free surface boundary conditions was fully taken into account and the raised panel method was employed to effectively solve the problem. The transom stern flow was also considered and the panel on the hull was generated using the panel cutting method. Numerical calculations were performed for KCS(KRISO Container Ship) hull form and compared with the experimental data to confirm the validity of the method. The comparison with the conventional free surface panel method was also accomplished. It is confirmed that new method gives more reliable results than the conventional method.

수요관리 투자사업에 대한 대안적 비용효과 분석 기법 도입 및 실제 적용 (A Study on Adoption of Alternative Cost-effectiveness Analysis Method for the DSM Investment Program and Actual Application)

  • 최봉하;박수억;이정태;이찬섭
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.243-248
    • /
    • 2008
  • The purpose of this study is to introduce alternative cost-effectiveness analysis method of DSM investment programs. This alternative method is Value Test method which consider the effects of DSM investment program on customer value. And this method was applied for actual DSM investment program in natural gas domain. By utilize this method to evaluate cost-effectiveness of DSM investment programs, it is expected to make right decision to enforce and complement those programs.

  • PDF

Comparison of Preparation Methods for the Quantification of Ginsenosides in Raw Korean Ginseng

  • Hong, Hee-Do;Sim, Eun-Mi;Kim, Kyung-Tack;Rho, Jeong-Hae;Rhee, Young-Kyung;Cho, Chang-Won
    • Food Science and Biotechnology
    • /
    • 제18권2호
    • /
    • pp.565-569
    • /
    • 2009
  • This study was conducted to evaluate the effects of different preparation methods on the recovery and quantification of ginsenosides in raw Korean ginseng (Panax ginseng C.A. Meyer). Eight major ginsenosides ($Rb_1$, $Rb_2$, $Rb_3$, Rc, Rd, Re, Rf, and $Rg_1$) were analyzed by high performance liquid chromatography (HPLC), after which the recovery and repeatability of the extraction of those ginsenosides using 3 different preparation methods were compared [A. direct extraction (DE) method, hot MeOH extraction/evaporation/direct dissolution; B. solid phase extraction (SPE) method, hot MeOH extraction/evaporation/dissolution/$C_{18}$ cartridge adsorption/MeOH elution; C. liquid-liquid extraction (LLE) method, hot MeOH extraction/evaporation/dissolution/n-BuOH fractionation]. Use of the DE method resulted in a significantly higher recovery of total ginsenosides than other methods and a relatively clear peak resolution. Use of the SPE and LLE methods resulted in clearer peak resolution, but lower ginsenoside recovery than the DE method. The LLE method showed the lowest ginsenoside recovery and repeatability among the 3 methods. Given that the DE method employed only extraction, evaporation, and a dissolution step (avoiding complicate and time consuming purification), this technique may be an effective method for the preparation and quantification of ginsenosides from raw Korean ginseng.

Determination of Polonium Nuclides in a Water Sample with Solvent Extraction Method

  • Lee, M.H.;Lee, C.H.;Song, K.;Kim, C.K.;Martin, P.
    • Bulletin of the Korean Chemical Society
    • /
    • 제31권9호
    • /
    • pp.2488-2492
    • /
    • 2010
  • A method is described for the determination of the Po nuclides in a water sample. After the Po nuclides were purified from interfering elements in a water sample using a manganese dioxide precipitation followed by a solvent extraction method, the Po nuclides were deposited onto the silver plate. A large volume of the water sample was effectively pretreated with manganese dioxide precipitation method. To determine the optimum conditions for plating Po, the effects of the pH, volume, temperature and time on the Po deposition were investigated in hydrochloric acid solution. The investigated determination method of Po nuclides with solvent extraction was applied to a tap water sample.

MUSIC-based Diagnosis Algorithm for Identifying Broken Rotor Bar Faults in Induction Motors Using Flux Signal

  • Youn, Young-Woo;Yi, Sang-Hwa;Hwang, Don-Ha;Sun, Jong-Ho;Kang, Dong-Sik;Kim, Yong-Hwa
    • Journal of Electrical Engineering and Technology
    • /
    • 제8권2호
    • /
    • pp.288-294
    • /
    • 2013
  • The diagnosis of motor failures using an on-line method has been the aim of many researchers and studies. Several spectral analysis techniques have been developed and are used to facilitate on-line diagnosis methods in industry. This paper discusses the first application of a motor flux spectral analysis to the identification of broken rotor bar (BRB) faults in induction motors using a multiple signal classification (MUSIC) technique as an on-line diagnosis method. The proposed method measures the leakage flux in the radial direction using a radial flux sensor which is designed as a search coil and is installed between stator slots. The MUSIC technique, which requires fewer number of data samples and has a higher detection accuracy than the traditional fast Fourier transform (FFT) method, then calculates the motor load condition and extracts any abnormal signals related to motor failures in order to identify BRB faults. Experimental results clearly demonstrate that the proposed method is a promising candidate for an on-line diagnosis method to detect motor failures.

Follicular Unit Classification Method Using Angle Variation of Boundary Vector for Automatic Hair Implant System

  • Kim, Hwi Gang;Bae, Tae Wuk;Kim, Kyu Hyung;Lee, Hyung Soo;Lee, Soo In
    • ETRI Journal
    • /
    • 제38권1호
    • /
    • pp.195-205
    • /
    • 2016
  • This paper presents a novel follicular unit (FU) classification method based on an angle variation of a boundary vector according to the number of hairs in several FU images. The recently developed robotic FU harvest system, ARTAS, classifies through digital imaging the FU type based on the number of hairs with defects in the contour and outline profile of the FU of interest. However, this method has a drawback in that the FU classification is inaccurate because it causes unintended defects in the outline profile of the FU. To overcome this drawback, the proposed method classifies the FU's type by the number of variation points that are calculated using an angle variation a boundary vector. The experimental results show that the proposed method is robust and accurate for various FU shapes, compared to the contour-outline profile FU classification method of the ARTAS system.

부모.자녀건강학회지 논문분석 (창간호-2009) (Analysis of Research Papers Published in the Korean Parent-Child Health Journal (1998-2009))

  • 박혜숙;오진아
    • 부모자녀건강학회지
    • /
    • 제14권1호
    • /
    • pp.1-8
    • /
    • 2011
  • Purpose: This study was aimed to classify the major subjects and theme and to analyze the data collection and analysis method in research papers published in the Korean Parent-Child Health Journal of the Academic Society of Parent-Child Health since 1998. Methods: A total 152 studies published from the first edition to volume 12, number 2 were reviewed using structured analysis criteria developed by researchers; research type, research design, research subjects, research theme, data collection and analysis method. Research theme was founded 4 nursing domains. Data collection and analysis method of papers were limited to quantitative and qualitative researches. Results: One hundred papers conducted quantitative research; 79.0% used survey design. Most of the data collection and analysis method in quantitative research were self-reported questionnaire (69.4%) and parametric statistics respectively. The research subjects of sixty three papers were parent with well or child. The common domain studies was human related concepts such as raring. Conclusion: The findings of this study suggest that published studies have been improved and diversified, however, detailed and clear evaluation tool that assess study process and method should be developed as a way to further improve the quality of published papers in the Korean Parent-Child Health Journal.

  • PDF

A Validation Model for the Statistical Power Balance Method Using a Reverberation Chamber

  • Lee, Young Seung;Choi, Sung Woong;Park, Seung Keun
    • Journal of electromagnetic engineering and science
    • /
    • 제13권3호
    • /
    • pp.192-194
    • /
    • 2013
  • This paper proposes a validation model using a reverberation chamber for verification of the effectiveness and accuracy of the statistical power balance (PWB) method. The PWB method treats electromagnetic (EM) field distributions in certain environments as a representative value of an "ensemble" average, so a reverberation chamber is utilized as a testing apparatus to experimentally simulate the sets of measurement field "ensemble" inside a complex environment. Measurements are performed with various test conditions for environmental loss using flat absorbers, and front and side doors of the chamber. Comparison between the PWB analysis and the measurement results shows good agreement, indicating the usefulness of this statistical analysis method for stating the electromagnetic field inside the EM zone as a representative value to general structures.

Quality and characteristics of fermented ginseng seed oil based on bacterial strain and extraction method

  • Lee, Myung-Hee;Rhee, Young-Kyoung;Choi, Sang-Yoon;Cho, Chang-Won;Hong, Hee-Do;Kim, Kyung-Tack
    • Journal of Ginseng Research
    • /
    • 제41권3호
    • /
    • pp.428-433
    • /
    • 2017
  • Background: In this study, the fermentation of ginseng seeds was hypothesized to produce useful physiologically-active substances, similar to that observed for fermented ginseng root. Ginseng seed was fermented using Bacillus, Pediococcus, and Lactobacillus strains to extract ginseng seed oil, and the extraction yield, color, and quantity of phenolic compounds, fatty acids, and phytosterol were then analyzed. Methods: The ginseng seed was fermented inoculating 1% of each strain on sterilized ginseng seeds and incubating the seeds at $30^{\circ}C$ for 24 h. Oil was extracted from the fermented ginseng seeds using compression extraction, solvent extraction, and supercritical fluid extraction. Results and Conclusion: The color of the fermented ginseng seed oil did not differ greatly according to the fermentation or extraction method. The highest phenolic compound content recovered with the use of supercritical fluid extraction combined with fermentation using the Bacillus subtilis Korea Food Research Institute (KFRI) 1127 strain. The fatty acid composition did not differ greatly according to fermentation strain and extraction method. The phytosterol content of ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method was highest at 983.58 mg/100 g. Therefore, our results suggested that the ginseng seed oil fermented with Bacillus subtilis KFRI 1127 and extracted using the supercritical fluid method can yield a higher content of bioactive ingredients, such as phenolics, and phytosterols, without impacting the color or fatty acid composition of the product.