• Title/Summary/Keyword: engineering optimization

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Applications of Fuzzy Theory on The Location Decision of Logistics Facilities (퍼지이론을 이용한 물류단지 입지 및 규모결정에 관한 연구)

  • 이승재;정창무;이헌주
    • Journal of Korean Society of Transportation
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    • v.18 no.1
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    • pp.75-85
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    • 2000
  • In existing models in optimization, the crisp data improve has been used in the objective or constraints to derive the optimal solution, Besides, the subjective environments are eliminated because the complex and uncertain circumstances were regarded as Probable ambiguity, In other words those optimal solutions in the existing models could be the complete satisfactory solutions to the objective functions in the Process of application for industrial engineering methods to minimize risks of decision-making. As a result of those, decision-makers in location Problems couldn't face appropriately with the variation of demand as well as other variables and couldn't Provide the chance of wide selection because of the insufficient information. So under the circumstance. it has been to develop the model for the location and size decision problems of logistics facility in the use of the fuzzy theory in the intention of making the most reasonable decision in the Point of subjective view under ambiguous circumstances, in the foundation of the existing decision-making problems which must satisfy the constraints to optimize the objective function in strictly given conditions in this study. Introducing the Process used in this study after the establishment of a general mixed integer Programming(MIP) model based upon the result of existing studies to decide the location and size simultaneously, a fuzzy mixed integer Programming(FMIP) model has been developed in the use of fuzzy theory. And the general linear Programming software, LINDO 6.01 has been used to simulate, to evaluate the developed model with the examples and to judge of the appropriateness and adaptability of the model(FMIP) in the real world.

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Process Optimization of Dextran Production by Leuconostoc sp. strain YSK. Isolated from Fermented Kimchi (김치로부터 분리된 Leuconostoc sp. strain YSK 균주에 의한 덱스트란 생산 조건의 최적화)

  • Hwang, Seung-Kyun;Hong, Jun-Taek;Jung, Kyung-Hwan;Chang, Byung-Chul;Hwang, Kyung-Suk;Shin, Jung-Hee; Yim, Sung-Paal;Yoo, Sun-Kyun
    • Journal of Life Science
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    • v.18 no.10
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    • pp.1377-1383
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    • 2008
  • A bacterium producing non- or partially digestible dextran was isolated from kimchi broth by enrichment culture technique. The bacterium was identified tentatively as Leuconostoc sp. strain SKY. We established the response surface methodology (Box-Behnken design) to optimize the principle parameters such as culture pH, temperature, and yeast extract concentration for maximizing production of dextran. The ranges of parameters were determined based on prior screening works done at our laboratory and accordingly chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 1, 5, and 9 g/l yeast extract. Initial concentration of sucrose was 100 g/l. The mineral medium consisted of 3.0 g $KH_2PO_4$, 0.01 g $FeSO_4{\cdot}H_2O$, 0.01 g $MnSO_4{\cdot}4H_2O$, 0.2 g $MgSO_4{\cdot}7H_2O$, 0.01 g NaCl, and 0.05 g $CaCO_3$ per 1 liter deionized water. The optimum values of pH and temperature, and yeast extract concentration were obtained at pH (around 7.0), temperature (27 to $28^{\circ}C$), and yeast extract (6 to 7 g/l). The best dextran yield was 60% (dextran/g sucrose). The best dextran productivity was 0.8 g/h-l.

Study on an Effective Decellularization Technique for Cardiac Valve, Arterial Wall and Pericardium Xenographs: Optimization of Decellularization (이종 심장 판막 및 대혈관 이식편과 심낭에서 효과적인 탈세포화 방법에 관한 연구: 탈세포화의 최적화)

  • Park, Chun-Soo;Kim, Yong-Jin;Sung, Si-Chan;Park, Ji-Eun;Choi, Sun-Young;Kim, Woong-Han;Kim, Kyung-Hwan
    • Journal of Chest Surgery
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    • v.41 no.5
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    • pp.550-562
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    • 2008
  • Background: We attempted to reproduce a previously reported method that is known to be effective for decellularization, and we sought to find the optimal condition for decellularization by introducing some modifications to this method. Material and Method: Porcine semilunar valves, arterial walls and pericardium were processed for decellularization with using a variety of combinations and concentrations of decellularizing agents under different conditions of temperature, osmolarity and incubation time. The degree of decellularization and the preservation of the extracellular matrix were evaluated by staining with hematoxylin and eosin and with alpha-Gal and DAPI in some of the decellularized tissues. Result: Decellularization was achieved in the specimens that were treated with sodium deoxycholate, sodium dodesyl sulfate, Triton X-100 and sodium dodesyl sulfate with Triton X-100 as single-step methods, and this was also achieved in the specimens that were treated with hypotonic solution ${\rightarrow}$ Triton X-100 ${\rightarrow}$ sodium dodesyl sulfate, sodium deoxycholate ${\rightarrow}$ hypotonic solution ${\rightarrow}$ sodium dodesyl sulfate, and hypotonic solution sodium dodesyl sulfate as multi-step methods. Conclusion: Considering the number and the amount of the chemicals that were used, the incubation time and the degree of damage to the extracellular matrix, a single-step method with sodium dodesyl sulfate and Triton X-100 and a multi-step method with hypotonic solution followed by sodium dodesyl sulfate were both relatively optimal methods for decellularization in this study.

Opportunity Tree Framework Design For Optimization of Software Development Project Performance (소프트웨어 개발 프로젝트 성능의 최적화를 위한 Opportunity Tree 모델 설계)

  • Song Ki-Won;Lee Kyung-Whan
    • The KIPS Transactions:PartD
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    • v.12D no.3 s.99
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    • pp.417-428
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    • 2005
  • Today, IT organizations perform projects with vision related to marketing and financial profit. The objective of realizing the vision is to improve the project performing ability in terms of QCD. Organizations have made a lot of efforts to achieve this objective through process improvement. Large companies such as IBM, Ford, and GE have made over $80\%$ of success through business process re-engineering using information technology instead of business improvement effect by computers. It is important to collect, analyze and manage the data on performed projects to achieve the objective, but quantitative measurement is difficult as software is invisible and the effect and efficiency caused by process change are not visibly identified. Therefore, it is not easy to extract the strategy of improvement. This paper measures and analyzes the project performance, focusing on organizations' external effectiveness and internal efficiency (Qualify, Delivery, Cycle time, and Waste). Based on the measured project performance scores, an OT (Opportunity Tree) model was designed for optimizing the project performance. The process of design is as follows. First, meta data are derived from projects and analyzed by quantitative GQM(Goal-Question-Metric) questionnaire. Then, the project performance model is designed with the data obtained from the quantitative GQM questionnaire and organization's performance score for each area is calculated. The value is revised by integrating the measured scores by area vision weights from all stakeholders (CEO, middle-class managers, developer, investor, and custom). Through this, routes for improvement are presented and an optimized improvement method is suggested. Existing methods to improve software process have been highly effective in division of processes' but somewhat unsatisfactory in structural function to develop and systemically manage strategies by applying the processes to Projects. The proposed OT model provides a solution to this problem. The OT model is useful to provide an optimal improvement method in line with organization's goals and can reduce risks which may occur in the course of improving process if it is applied with proposed methods. In addition, satisfaction about the improvement strategy can be improved by obtaining input about vision weight from all stakeholders through the qualitative questionnaire and by reflecting it to the calculation. The OT is also useful to optimize the expansion of market and financial performance by controlling the ability of Quality, Delivery, Cycle time, and Waste.

Optimization for Solid Culture of Phellinus sp. by Response Surface Methodology (반응표면방법에 의한 Phellinus sp. 고체배양의 최적화)

  • Kang, Tae-Su;Kang, An-Seok;Sohn, Hyung-Rac;Kang, Mi-Sun;Lim, Yaung-Iee;Lee, Shin-Young;Jung, Sung-Mo
    • The Korean Journal of Mycology
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    • v.26 no.2 s.85
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    • pp.265-274
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    • 1998
  • This study was carried out to obtain the basic data for an artificial cultivation of Phellinus sp.. The optimum conditions for the mycelial growth on the different sawdusts (Quercus aliena, Morns alba and Alnus japonica) substrate of an isolated Phellinus sp. were optimized by response surface methodology. The ratio of rice bran addition to sawdust and the suitable moisture content for the mycelial growth in the all sawdust media were about 30% (w/w) and $65{\sim}70%$ (w/v), respectively. The initial pHs for the mycelial growth of Quercus aliena and Morns alba were in the range of $pH\;5{\sim}6$, whereas Alnus japonica was obtained at pH 6. The optimum temperature for the mycelial growth was about $25{\sim}30^{\circ}C$, depending on the different kinds of wood substrates. From the response surface analysis, the values of independent variables of Quercus aliena at stationary points were determined to be 31.01 % (w/w) of rice bran, pH of 5.31 and 69.03% (w/v) of moisture content, and the expected value of mycelial growth was about 8.32 cm. Both the ratio of rice bran addition to sawdust $(X_1)$ and moisture content $(X_3)$ were effective to the mycelial growth. In the case of Morns alba, the ratio of rice bran addition to sawdust, initial pH and moisture content at the stationary points were 28.77% (w/w), 5.28 and 69.8 (w/v),respectively, and the expected mycelial growth of 7.60 cm was obtained. Stationary points for the mycelial growth in the sawdust media of Alnus japonica were 28.74% (w/w) of rice bran, pH of 6. 04 and 66.96% (w/v) of moisture content, and the expected values of mycelial growth was about 5.38 cm. Based on the above results, there was correlations between the mycelial growth and independent variables, and the effect of rice bran $(X_1)$ and initial pH $(X_2)$ for the mycelial growth were higher than the moisture content $(X_3)$. The optimum species of sawdust media for the my celial growth of Phellinus sp. was in the order of Quercus aliena > Morns alba > Alnus japonica.

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The Optimal Configuration of Arch Structures Using Force Approximate Method (부재력(部材力) 근사해법(近似解法)을 이용(利用)한 아치구조물(構造物)의 형상최적화(形狀最適化)에 관한 연구(研究))

  • Lee, Gyu Won;Ro, Min Lae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.95-109
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    • 1993
  • In this study, the optimal configuration of arch structure has been tested by a decomposition technique. The object of this study is to provide the method of optimizing the shapes of both two hinged and fixed arches. The problem of optimal configuration of arch structures includes the interaction formulas, the working stress, and the buckling stress constraints on the assumption that arch ribs can be approximated by a finite number of straight members. On the first level, buckling loads are calculated from the relation of the stiffness matrix and the geometric stiffness matrix by using Rayleigh-Ritz method, and the number of the structural analyses can be decreased by approximating member forces through sensitivity analysis using the design space approach. The objective function is formulated as the total weight of the structures, and the constraints are derived by including the working stress, the buckling stress, and the side limit. On the second level, the nodal point coordinates of the arch structures are used as design variables and the objective function has been taken as the weight function. By treating the nodal point coordinates as design variable, the problem of optimization can be reduced to unconstrained optimal design problem which is easy to solve. Numerical comparisons with results which are obtained from numerical tests for several arch structures with various shapes and constraints show that convergence rate is very fast regardless of constraint types and configuration of arch structures. And the optimal configuration or the arch structures obtained in this study is almost the identical one from other results. The total weight could be decreased by 17.7%-91.7% when an optimal configuration is accomplished.

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Optimum Design of Two Hinged Steel Arches with I Sectional Type (SUMT법(法)에 의(依)한 2골절(滑節) I형(形) 강재(鋼材) 아치의 최적설계(最適設計))

  • Jung, Young Chae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.3
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    • pp.65-79
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    • 1992
  • This study is concerned with the optimal design of two hinged steel arches with I cross sectional type and aimed at the exact analysis of the arches and the safe and economic design of structure. The analyzing method of arches which introduces the finite difference method considering the displacements of structure in analyzing process is used to eliminate the error of analysis and to determine the sectional force of structure. The optimizing problems of arches formulate with the objective functions and the constraints which take the sectional dimensions(B, D, $t_f$, $t_w$) as the design variables. The object functions are formulated as the total weight of arch and the constraints are derived by using the criteria with respect to the working stress, the minimum dimension of flange and web based on the part of steel bridge in the Korea standard code of road bridge and including the economic depth constraint of the I sectional type, the upper limit dimension of the depth of web and the lower limit dimension of the breadth of flange. The SUMT method using the modified Newton Raphson direction method is introduced to solve the formulated nonlinear programming problems which developed in this study and tested out throught the numerical examples. The developed optimal design programming of arch is tested out and examined throught the numerical examples for the various arches. And their results are compared and analyzed to examine the possibility of optimization, the applicablity, the convergency of this algorithm and with the results of numerical examples using the reference(30). The correlative equations between the optimal sectional areas and inertia moments are introduced from the various numerical optimal design results in this study.

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Optimization of Processing Conditions for the Production of Puffed Rice (팽화미 제조 공정조건의 최적화)

  • Cheon, Hee Soon;Cho, Won Il;Jhin, Changho;Back, Kyeong Hwan;Ryu, Kyung Heon;Lim, Su Youn;Chung, Myong Soo;Choi, Jun Bong;Lim, Taehwan;Hwang, Keum Taek
    • Culinary science and hospitality research
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    • v.21 no.1
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    • pp.77-89
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    • 2015
  • The objective of this study was to optimize processing conditions for the production of an instant puffed rice product using response surface methodology (RSM) and contour analysis. Sensory and texture qualities, and physical properties of the puffed rice were analyzed with various processing conditions related to drying and puffing temperature, and moisture content. Preference, color intensity, cohesiveness, rehydration ratio, density and lightness of the puffed rice product significantly varied depending on the processing conditions. The responses showed high $R^2$ values (0.623, 0.852, 0.735, 0.688, and 0.790) and lack-of-fit. Rehydration ratio was found to have a negative correlation with density in the condition of drying and puffing temperature. Lightness and preference scores of the puffed rice increased as the moisture content increased. According to RSM, the preference scores were very highly related to the moisture content, and the optimum processing conditions of the puffed rice product were at $40^{\circ}C$ of drying temperature, with 11.0% of moisture content, and at $232.7^{\circ}C$ of puffing temperature.

Optimization of the Acetic Acid Fermentation Condition of Apple Juice (사과식초 제조를 위한 사과주스의 초산발효 최적화)

  • Kang, Bok-Hee;Shin, Eun-Jeong;Lee, Sang-Han;Lee, Dong-Sun;Hur, Sang-Sun;Shin, Kee-Sun;Kim, Seong-Ho;Son, Seok-Min;Lee, Jin-Man
    • Food Science and Preservation
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    • v.18 no.6
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    • pp.980-985
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    • 2011
  • This study was conducted to determine the acetic-acid fermentation properties of apple juice (initial alcohol content, apple juice concentration, acetic-acid content, and inoculum size) in flask scale. At the acetic-acid fermentation of apple juice with 3, 5, 7, and 9% initial alcohol content, the maximum acidity after 10-day fermentation was 5.88% when the initial alcohol content was 5%. The acetic-acid fermentation did not proceed normally when the initial alcohol content was 9%. When the initial Brix was $1^{\circ}$, the acidity gradually increased, and the acidity after 12-day acetic-acid fermentation was 4.48%. Above 4% acidity was attained faster when the apple juice concentration was 5 and 10 $^{\circ}Brix$ than when it was 1 and 14 $^{\circ}Brix$. When the initial acidity was 1% or above (0.3, 0.5, 1.0, and 2.0%), the acetic-acid fermentation proceeded normally. The acetic-acid fermentation also proceeded normally when the inoculum sizes were 10 and 15%, and the acidity after eight-day acetic-acid fermentation was 5.60 and 6.05%, respectively. Therefore, the following were considered the optimal acetic-acid fermentation conditions for apple cider vinegar: 5% initial alcohol content, 5 $^{\circ}Brix$ or above apple juice concentration, 1.0% or above initial acidity, and 10% or above inoculum size. Apple cider vinegar with above 5% acidity can be produced within 48 h under the following acetic-acid fermentation conditions: 7% initial alcohol content, about 1% initial acidity, and 10% inoculum volume at $30^{\circ}C$, 30 rpm, and 1.0 vvm, using 14 $^{\circ}Brix$ apple juice in a mini-jar fermentor as a pre-step for industrial-scale adaptation.

Analysis of Skin Color Pigments from Camera RGB Signal Using Skin Pigment Absorption Spectrum (피부색소 흡수 스펙트럼을 이용한 카메라 RGB 신호의 피부색 성분 분석)

  • Kim, Jeong Yeop
    • KIPS Transactions on Software and Data Engineering
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    • v.11 no.1
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    • pp.41-50
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    • 2022
  • In this paper, a method to directly calculate the major elements of skin color such as melanin and hemoglobin from the RGB signal of the camera is proposed. The main elements of skin color typically measure spectral reflectance using specific equipment, and reconfigure the values at some wavelengths of the measured light. The values calculated by this method include such things as melanin index and erythema index, and require special equipment such as a spectral reflectance measuring device or a multi-spectral camera. It is difficult to find a direct calculation method for such component elements from a general digital camera, and a method of indirectly calculating the concentration of melanin and hemoglobin using independent component analysis has been proposed. This method targets a region of a certain RGB image, extracts characteristic vectors of melanin and hemoglobin, and calculates the concentration in a manner similar to that of Principal Component Analysis. The disadvantage of this method is that it is difficult to directly calculate the pixel unit because a group of pixels in a certain area is used as an input, and since the extracted feature vector is implemented by an optimization method, it tends to be calculated with a different value each time it is executed. The final calculation is determined in the form of an image representing the components of melanin and hemoglobin by converting it back to the RGB coordinate system without using the feature vector itself. In order to improve the disadvantages of this method, the proposed method is to calculate the component values of melanin and hemoglobin in a feature space rather than an RGB coordinate system using a feature vector, and calculate the spectral reflectance corresponding to the skin color using a general digital camera. Methods and methods of calculating detailed components constituting skin pigments such as melanin, oxidized hemoglobin, deoxidized hemoglobin, and carotenoid using spectral reflectance. The proposed method does not require special equipment such as a spectral reflectance measuring device or a multi-spectral camera, and unlike the existing method, direct calculation of the pixel unit is possible, and the same characteristics can be obtained even in repeated execution. The standard diviation of density for melanin and hemoglobin of proposed method was 15% compared to conventional and therefore gives 6 times stable.