• Title/Summary/Keyword: Standard solutions

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Changes of Ascorbic Acid Contents Induced from Gamma Irradiation, Heating and Microwave Treatments (방사선 조사, 가열 및 마이크로웨이브처리에 따른 Ascorbic Acid의 함량변화)

  • 변명우;이인숙;이경행;육홍선;강근옥
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.4
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    • pp.954-957
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    • 1999
  • The changes in L ascorbic acid content by processing treatments; gamma irradiation, heating and microwave were investigated using high performance liquid chromatography. The content of L ascorbic acid in standard solutions and citrus fruits decreased from 27.4 to 44.9% and from 6.9 to 21.9%, re spectively, by gamma irradiation doses in the range of 1 to 10 kGy. By heating treatments, L ascorbic acids in standard solutions and citrus fruits were destroyed 22.5 to 36.8% and 4.5 to 18.1%, respectively. By microwave treatment, L ascorbic acid content also decreased from 23.1 to 47.4% and from 6.5 to 22.6%, respectively.

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Problems and Solutions of Soil Fertility Enhancement in Korean Organic Farming (한국 토착유기농업의 토양비옥도 증진책의 문제점과 대안)

  • 손상목
    • Korean Journal of Organic Agriculture
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    • v.8 no.2
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    • pp.53-77
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    • 2000
  • This paper aims to point out the problems and solutions of soil fertility enhancement in Korean organic farming which does not harmonize with internationally recognized standard of organic agriculture such as Basic Standard of IFOAM, EU regulations, and guidelines of FAO/WHO codex alimentarius. The necessity of rotation, legume, green manure to enhance the soil fertility or organic farming system was discussed, and the reasons why salt accumulation including nitrate and phosphate in the rooted soil profiles was frequently occurred in Korean organic farmer's field also discussed. Soil testing for correct handling of organic fertilization was introduced to void the salt accumulation just applying the huge amount of organic fertilizer year to year to reach a maximum crop yield. In the conclusion it was suggested for Korean organic agriculture to make an effort to coincide it's regulation with internationally recognized standards for organic farming.

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Multi-objective Optimization of Vehicle Routing with Resource Repositioning (자원 재배치를 위한 차량 경로계획의 다목적 최적화)

  • Kang, Jae-Goo;Yim, Dong-Soon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.44 no.2
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    • pp.36-42
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    • 2021
  • This paper deals with a vehicle routing problem with resource repositioning (VRPRR) which is a variation of well-known vehicle routing problem with pickup and delivery (VRPPD). VRPRR in which static repositioning of public bikes is a representative case, can be defined as a multi-objective optimization problem aiming at minimizing both transportation cost and the amount of unmet demand. To obtain Pareto sets for the problem, famous multi-objective optimization algorithms such as Strength Pareto Evolutionary Algorithm 2 (SPEA2) can be applied. In addition, a linear combination of two objective functions with weights can be exploited to generate Pareto sets. By varying weight values in the combined single objective function, a set of solutions is created. Experiments accomplished with a standard benchmark problem sets show that Variable Neighborhood Search (VNS) applied to solve a number of single objective function outperforms SPEA2. All generated solutions from SPEA2 are completely dominated by a set of VNS solutions. It seems that local optimization technique inherent in VNS makes it possible to generate near optimal solutions for the single objective function. Also, it shows that trade-off between the number of solutions in Pareto set and the computation time should be considered to obtain good solutions effectively in case of linearly combined single objective function.

On the Regulation for Pronunciation of Loanwords in Korean (외래어의 표준 발음과 어문 규범)

  • Yi, Eun-gyeong
    • Cross-Cultural Studies
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    • v.38
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    • pp.405-431
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    • 2015
  • The purpose of this paper is to investigate how to decide pronunciation of loanwords in Korean language. There has not been a regulation for pronunciation of loanwords in Korean language. Even the dictionary published by the government does not provide any information about the pronunciation of loanwords. In this paper, some actual solutions are suggested for the pronunciation of loanwords. Korean language has Regulations of Standard Korean, Korean Orthography, Regulations on Hangeul Transcriptions on Loanwords and Pronunciation Methods of Standard Korean. These language standards could help to decide pronunciation of loanwords. Some pronunciations which could not be regulated by them must be presented in the standard pronunciation dictionary. For example, glottalization rule of 's' in many loanwords could be presented in the description of each loanword in the dictionary. However the pronunciation of loanwords must be similar to the spelling. If various pronunciations are allowed to one spelling, then people will be so confused by the discrepancy between pronunciation and spelling of loanwords.

Digital simulation of differential equations driven by white noise (백색잡음 미분방정식에 대한 디지탈 시뮬레이션)

  • 조항주
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.383-388
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    • 1991
  • This paper analizes two numerical integration methods, both based on the Runge Kutta 4-th order formula for deterministic systems, for digital simulation of a differential equation driven by white noise. It is shown that a "standard' Runge Kutta method for stochasitic systems yields solutions of Stratonovich differential equations, while Riggs and Phillips' method results in solutions of Ito differential equations. Therefore the white noise differential equation must be converted into the equivalent Ito equation before the latter method is used. Digital simulation results for a simple differential equation are also presented.nted.

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THE BOUNDEDNESS OF SOLUTIONS FOR STOCHASTIC DIFFERENTIAL INCLUSIONS

  • Yun, Yong-Sik
    • Bulletin of the Korean Mathematical Society
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    • v.40 no.1
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    • pp.159-165
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    • 2003
  • We consider the stochastic differential inclusion of the form $dX_t\;\in\;\sigma(t,\;X_t)db_t+b(t,\;X_t)dt$, where $\sigma$, b are set-valued maps, B is a standard Brownian motion. We prove the boundedness of solutions under the assumption that $\sigma$ and b satisfy the local Lipschitz property and linear growth.

Selection Problems in terms of Coefficients of Vairiation

  • Park, Chi-Hoon;Jeon, Jong-Woo;Kim, Woo-Chul
    • Journal of the Korean Statistical Society
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    • v.11 no.1
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    • pp.12-24
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    • 1982
  • Selection procedures are proposed for selecting the 'best' industrial process with the smallest fraction defective. For normally distributed industrial processes, this is equivalent to selecting in terms of coefficients of variation. For the case of known vairances, selection procedures by Bechhofer (1954), and Bechhofer and Turnball (1978) are appropriate. We treat this problem for the case of uknown variances with or without reference to a standard. The large sample solutions of design constants are tabulated and the performance of these approximate solutions are investigated.

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Study on the Physical Properties of New Developed Teat Cup Liner Compounds (신개발 유두컵 라이너용 고무조성물의 물리적 특성 조사)

  • Lee, Jeong-Chi
    • Journal of Veterinary Clinics
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    • v.24 no.2
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    • pp.201-207
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    • 2007
  • The teat cup liner compounds with improved physical property were developed using tri-polymer blend of natural rubber(NR), ethylene propylene diene monomer rubber(EPDM) and butyl rubber, and the changes of the physical properties of compounds were measured under various conditions such as standard, thermal, alkaline detergent and acid solutions aging conditions. The hardness of the new teat cup liner compound 1 was 50 and that of the compound 2 was 51 under standard condition. The tensile strength and elongation of the new compound 1 were $154kgf/cm^2$ and 675% under the standard condition, respectively. Also, those of the new compound 2 were 180 kgf/cm and 634% under the same condition. Their hardness were increased about $2{\sim}6%$ and the tensile strength and elongation were decreased about 10% under the $25^{\circ}C$ water and detergent solutions. Even though the new teat cup liner compounds exhibited so much decreased tensile properties under the $105^{\circ}C$ thermal aged condition, they sustained more stable aged physical properties including tensile strength and elongation than those of imported teat cup liner materials. Consequently, the new teat cup liner compounds would give prolonged lift cycle if they are used as a teat cup liner product.

Stability of Domoic Acid at Different Temperature, pH and Light (온도, pH 및 빛에 대한 Domoic Acid의 안정성)

  • Mok, Jong-Soo;Lee, Tae-Seek;Oh, Eun-Gyoung;Son, Kwang-Tae;Hwang, Hye-Jin;Kim, Ji-Hoe
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.1
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    • pp.8-14
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    • 2009
  • To prevent the food poisoning originated by consumption of shellfish contaminated with domoic acid, the quantitative analysis of domoic acid is to be very important. The stability of domoic acid at different temperature, pH and light was investigated using high performance liquid chromatography (HPLC). The mean recoveries of domoic acid in the methanol extracts from oyster (Crassostrea gigas), blue mussel (Mytilus edulis), short neck clam (Ruditapes philippinarum) and ark shell (Scapharca broughtonii) were 85.4-104.5%, 94.8-101.2%, 91.0-104.6%, and 95.7-109.6%, respectively. The working solutions of domoic acid standard were very stable for one month at $-18^{\circ}C$, $4^{\circ}C$, and room temperature. And domoic acid in the methanol extract from oyster was stable for a day at $4^{\circ}C$ and room temperature, and for a week at $-18^{\circ}C$. Therefore, this implies that quantitative analysis for domoic acid must consider the storage conditions of the standard solutions and the methanol extracts from shellfish. The standard solutions adjusted to pH 3-9 were also stable after heating at $121^{\circ}C$ for 30 min. The effect of light exposure on domoic acid was tested by exposing the methanol extracts to light. Domoic acid degraded slowly when the samples were kept in the dark (brown vial). However, following the light exposure the photodegradation became more rapid; no detectable domoic acid remained in $1.0{\mu}g/mL$ of methanol extract after 5 hours.