• Title/Summary/Keyword: addition method

Search Result 21,771, Processing Time 0.057 seconds

A Study on the Shape Optimization of a Cutout Using Evolutionary Structural Optimization Method (진화 구조 최적화 기법을 이용한 개구부의 형상 최적화에 관한 연구)

  • 류충현;이영신
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.369-372
    • /
    • 2000
  • ESO(Evolutionary Structural Optimization) method is known that elements involved low stress value are removed from the previous model or that elements are added around elements involved high stress level on it and then the optimized model is obtained with required weight. Rejection ratio/addition ratio and evolutionary ratio are predefined and elements having lower/higher stress than reference stress, which average Mises stress on edge elements times rejection ratio, are deleted/added. In this study, when the plate having a cutout is subjected various in-plane load, a cutout shape is optimized using ESO method. ANSYS is used to analyse a finite element model and optimization procedure is made by APDL (ANSYS Parametric Design Language). ESO method is useful in rather than a complex structure optimization as well as a cutout shape optimization.

  • PDF

Seismic behavior of three dimensional concrete rectangular containers including sloshing effects

  • Mirzabozorg, H.;Hariri-Ardebili, M.A.;Nateghi A., R.
    • Coupled systems mechanics
    • /
    • v.1 no.1
    • /
    • pp.79-98
    • /
    • 2012
  • In the present paper, the three-dimensional model of a typical rectangular concrete tank is excited using an artificial and a natural three components earthquake ground motion and the staggered displacement method is utilized for solving the coupled problem of the tank-contained liquid system in time domain. In the proposed method, surface sloshing of the liquid is taken into account in addition to the impulsive term and the appropriate damping values are applied on both of them. The resulted responses are compared with those obtained from the ABAQUS finite element software. It is found that the convective term affects responses extensively and must be considered in seismic design/safety assessment of storage tanks. In addition, the utilized method for solving the coupled problem is stable during the conducted general dynamic analyses and is able to capture the expected phenomena.

A Study on the Basic Properties of Exterior Insulation Plasterer Finishing Materials by Addition of Calcium Carbonate Powder (탄산칼슘계 분말 첨가에 따른 외단열 미장 마감재의 기초물성에 관한 연구)

  • Shin, Joung-Hyeon;Jo, Su-Yeon;Jung, Ui-In;Kim, Bong-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2021.05a
    • /
    • pp.213-214
    • /
    • 2021
  • External insulation method is used to conserve energy of buildings. However, the current external insulation method uses organic insulating materials to become a diffusion path in case of fire. In this study, the purpose of this study is to provide basic data on the required performance of the plastering material according to the CaCO3 powder addition of the finishing material of the external insulation method. In Figure 1, when powder was added, the adhesion strength decreased by 30% to 35% at 10% and 0% to 50% at 20% compared to Plain. In Figure 2, the moisture permeability increases approximately twice when powder is added. The results for the water absorption coefficient are shown in Figure 3.

  • PDF

The Establishment of Improvement Direction through Case Analysis of Cost Standards in Overseas Construction Engineering (해외 건설엔지니어링분야 대가기준 사례분석을 통한 개선방향 마련)

  • Ko, Hyun A;Han, Jae Goo
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2020.06a
    • /
    • pp.165-166
    • /
    • 2020
  • The standard for the cost calculation in the field of domestic construction engineering can be largely divided into the construction cost ratio method and the actual cost addition method. However, the standard for calculating the cost of the construction cost ratio method is a trend to switch to the actual cost addition method due to limitations such as not reflecting the characteristics of the construction. Therefore, this study aims to derive implications by investigating and analyzing examples of cost standards in the field of overseas construction engineering, such as the United States, and deriving directions for improvement in domestic cost standards in the future.

  • PDF

Accurate Measurement of Arsenic in Laver by Gravimetric Standard Addition Method Combined with High Resolution Inductively Coupled Plasma Mass Spectrometry

  • Lee, Kyoung-Seok;Kim, Hyeon-Ji;Yim, Yong-Hyeon;Kim, Jeongkwon;Hwang, Euijin
    • Mass Spectrometry Letters
    • /
    • v.5 no.2
    • /
    • pp.57-61
    • /
    • 2014
  • A gravimetric standard addition method combined with internal standard calibration has been successfully developed for the accurate analysis of total arsenic in a laver candidate reference material. A model equation for the gravimetric standard addition approach using an internal standard was derived to determine arsenic content in samples. Handlings of samples, As standard and internal standard were carried out gravimetrically to avoid larger uncertainty and variability involved in the volumetric preparation. Germanium was selected as the internal standard because of its close mass to the arsenic to minimize mass-dependent bias in mass spectrometer. The ion signal ratios of $^{75}As^+$ to $^{72}Ge^+$ (or $^{73}Ge^+$) were measured in high resolution mode ($R{\geq}10,000$) to separate potential isobaric interferences by high resolution ICP/MS. For method validation, the developed method was applied to the analysis of arsenic content in the NMIJ 7402-a codfish certified reference material (CRM) and the result was $37.07mg{\cdot}kg^{-1}{\pm}0.45mg{\cdot}kg^{-1}$ which is in good agreement with the certified value, $36.7mg{\cdot}kg^{-1}{\pm}1.8mg{\cdot}kg^{-1}$. Finally, the certified value of the total arsenic in the candidate laver CRM was determined to be $47.15mg{\cdot}kg^{-1}{\pm}1.32mg{\cdot}kg^{-1}$ (k = 2.8 for 95% confidence level) which is an excellent result for arsenic measurement with only 2.8 % of relative expanded uncertainty.

The Effects of Electric Grill and Microwave Oven Reheating Methods on the Quality Characteristics of Precooked Ground Pork Patties with Different NaCl and Phosphate Levels (전기그릴과 전자레인지 재가열이 소금농도와 인산염 첨가수준에 따른 분쇄 돈육 패티의 품질 특성에 미치는 영향)

  • Choi, Ji-Hun;Jeong, Jong-Youn;Kim, Hack-Youn;An, Kwang-Il;Kim, Cheon-Jei
    • Food Science of Animal Resources
    • /
    • v.28 no.5
    • /
    • pp.535-542
    • /
    • 2008
  • The objective of this study was to determine the effects of different reheating methods on the quality characteristics of precooked ground pork patties with different combinations of salt (1, 2%) and phosphate (0, 0.3%). The cooking and reheating methods used were the electric grill and the microwave oven. The cooking method and the addition of phosphate had detectable effects on the quality characteristics of ground pork patties. The reheating rate by microwave oven was faster than by electric grill, and decreased with increases in salt and the addition of phosphate. Cooking loss and reduction in patty diameter after reheating by microwave oven were higher than by electric grill, and these values decreased with increasing of salt/phosphate levels. The pH of patties with added phosphate was significantly higher than patties without phosphate, and no significant difference in pH was observed among patties reheated by each method. The patties reheated by electric grill had higher moisture contents than those reheated by electric grill, and the addition of phosphate resulted in higher moisture contents. The hardness of patties reheated by electric grill was lower than patties reheated by microwave oven, and the addition of phosphate increased the hardness with both reheating methods.

An Experimental Study on the Relationship Between Temperature and Pressure Inside the Cup During Cupping Procedures

  • Lee, Ha Lim;An, Soo Kwang;Lee, Jae Yong;Shim, Dong Wook;Lee, Byung Ryul;Yang, Gi Young
    • Journal of Acupuncture Research
    • /
    • v.38 no.1
    • /
    • pp.41-46
    • /
    • 2021
  • Background: Pressure changes related to temperature variation during cupping may lead to dropout. This study aimed to investigate pressure changes related to temperature variations in the cup during the cupping procedure. Methods: Changes in temperature and pressure were measured for 15 minutes after the procedure was performed using the alcohol rub method with glass cups and with the addition of infrared irradiation. Changes in temperature and pressure were also measured for 15 minutes after pumping 3 times using the valve suction method, and with the addition of infrared irradiation. Results: In a comparison between the alcohol rub method with glass cups and with the addition of infrared irradiation, the negative pressure increased over time in the absence of infrared irradiation, whereas it decreased when performed with infrared irradiation p = 0.094. However, in a comparison between pumping 3 times using the valve suction method, and with the addition of infrared irradiation, the negative pressure decreased in both cases, but this was more significant with infrared irradiation p = 0.172. There was a significantly higher temperature in the glass cups (p = 0.004) and the valve cups (p = 0.001) exposed to infrared radiation, compared with no infrared irradiation. Conclusion: The reduction in negative pressure inside the cups exposed to infrared radiation was greater than without infrared irradiation. Temperature increases inside the cup can lead to the risk of dropout.

Automatic Suggestion for PubMed Query Reformulation

  • Tuan, Luu Anh;Kim, Jung-Jae
    • Journal of Computing Science and Engineering
    • /
    • v.6 no.2
    • /
    • pp.161-167
    • /
    • 2012
  • Query reformulation is an interactive process of revising user queries according to the query results. To assist biomedical researchers in this process, we present novel methods for automatically generating query reformulation suggestions. While previous work on query reformulation focused on addition of words to user queries, our method can deal with three types of query reformulation (i.e., addition, removal and replacement). The accuracy of the method for the addition type is ten times better than PubMed's "Also try", while the execution time is short enough for practical use.

Effect of $ZrO_2$ Addition on the Synthesis and Microwave Dielectric Properties of $Ba_2Ti_9O_{20}$ Fabricated by Oxalate method (수산염법에 의한 $Ba_2Ti_9O_{20}$의 합성과 유전특성에 미치는 $ZrO_2$ 첨가의 영향)

  • 박재원;이헌식;이병하
    • Journal of the Korean Ceramic Society
    • /
    • v.31 no.8
    • /
    • pp.835-840
    • /
    • 1994
  • In this study, the synthesis of Ba2Ti9O20 powder having chemically homogeneous and highly pure fine particle size distribution was attempted by the oxalate method. And the effects of ZrO2 addition was investigated. The four compositions (X=0, 0.028, 0.048, 0.068) of Ba2(Ti9-x, Zrx)O20 were prepared by precipitation reaction of BaCl2, TiCl4, and ZrOCl2, with oxalic acid and NH4OH acting as a precipitating agent and a pH regulator respectively, in aqueous solution. In case of 4.8 mol% ZrO2 addition, the single phase Ba2Ti9O20 was obtained at 120$0^{\circ}C$ and its dielectric properties was excellent showing K=40.5, Q=4621 at 5.4 GHz.

  • PDF

The realization of secondary voltage controller using real-time digital simulator(Hypersim) (실시간 디지털 시뮬레이터(Hypersim)을 이용한 이차적 전압제어 제어기 구현)

  • Kim, Bong-Sik;Seo, Sang-Soo;Lee, Byong-Jin;Song, In-Jun;Shin, Jeong-Hoon;Kim, Tae-Kyun
    • Proceedings of the KIEE Conference
    • /
    • 2006.11a
    • /
    • pp.269-271
    • /
    • 2006
  • In power system, the reactive power is closely associated with voltage. In addition Reactive power has localized characteristic. Recently wide area blackout caused by reactive power imbalance. Therefore it is important to control reactive power considering its characteristic. Until now maintenance of system voltage has been controlled by shunt compensation rather than generators. However because of a large time-constant, shunt compensators are difficult to manage disturbances immediately. In addition shunt compensation has discrete characteristic, which make disturbances in system. In this paper we studied the voltage maintenance method of local buses by controlling the reactive power output of a generator which is closely related a load bus in addition the proposed method was verified by test system.

  • PDF