• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.19-27
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• 2009

This paper presents a newly developed optimization algorithm, the Bee Optimization Algorithm (BeeOA), to solve the economic power dispatch (EPD) problem. The authors have developed a derivative free and global optimization technique based on the working of the honey bee. The economic power dispatch problem is a nonlinear constrained optimization problem. Classical optimization techniques fail to provide a global solution and evolutionary algorithms provide only a good enough solution. The proposed approach has been examined and tested on two test systems with different objectives. A simple power dispatch problem is tested first on 6 generators and then the algorithm is demonstrated on 13 thermal unit systems whose incremental fuel cost function takes into account the value point loading effect. The results are promising and show the effectiveness and robustness of the proposed approach over recently reported methods.

• Steel and Composite Structures
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• 제39권3호
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• pp.229-241
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• 2021

This work focused on aluminum foam sandwich (AFS) with different foam core densities and different face-sheet thicknesses subjected to constant amplitude three-point bending cyclic loading to study its fatigue performance. The experiments were conducted out by a high frequency fatigue test machine named GPS-100. The experimental results showed that the fatigue life of AFS decreased with the increasing loading level and the structure was sensitive to cyclic loading, especially when the loading level was under 20%. S-N curves of nine groups of AFS specimens were obtained and the fatigue life of AFS followed three-parameter lognormal distribution well. AFS under low cyclic loading showed pronounced cyclic hardening and the static strength after fatigue test increased. For the same loading level, effects of foam core density and face-sheet thickness on the fatigue life of AFS structure were trade-off and for the same loading value, the fatigue life of AFS increased with aluminum foam core density or face-sheet thickness monotonously. Core shear was the main failure mode in the present study.

• 동아시아식생활학회지
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• 제26권1호
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• pp.63-72
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• 2016

Asparagus (Asparagus officinalis L.) is a vegetable that has been reported to have a variety of pharmacological effects such as antioxidant and antitumor effects. In order to examine the quality characteristics and antioxidant characteristics of asparagus, asparagus Sulgidduck was prepared with different ratios of freeze-dried asparagus powder (0%, 0.5%, 1%, 2%, 3%, and 4%, w/w). As asparagus powder content in Sulgidducks increased, moisture contents of Sulgidducks decreased significantly. The pH of Sulgidducks decreased with higher amounts of added asparagus powder. Furthermore, the pH of Sulgidduck containing 4% asparagus powder showed the lowest value of 5.98. As asparagus powder content of Sulgidducks increased, L-value (lightness) decreased while a-value (redness) and b-value (yellowness) increased. In texture analysis, hardness and chewiness of Sulgidducks with freeze-dried asparagus powder increased with higher asparagus powder. The cohesiveness of Sulgidducks containing 4% asparagus powder showed the lowest value of 65.72%. Both total polyphenol content and DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity increased significantly with higher levels of asparagus powder content in Sulgidducks. In the sensory evaluation using a 7-point test, Sulgidduck containing 2% asparagus powder showed the highest sensory preference scores. Therefore, the results of this study suggest addition of 2% asparagus powder is the most appropriate ratio for making Sulgidduck with optimal quality characteristics.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2011년도 춘계학술발표회 논문집
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• pp.235-241
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• 2011

Effects of thermal aging on color variations of various papers were evaluated. With thermal aging, most of papers showed a special trend in $a^*$-$b^*$ plane: $a^*$ (red-green) values of the samples were reduced at beginning and after a turning point it was increased while $b^*$ (blue-yellow) was kept increased (yellowing of paper). In case of filter paper which consists of chemical pulps, the changes in $a^*$ value was occurred late compared with other samples. In case of the copy paper with optical brightening agent, the turning point in $a^*$ was not observed while a constant increase in $b^*$ was observed. In case of color paper, no specific trends in $a^*$-$b^*$ were found.

• 농업과학연구
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• 제26권2호
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• pp.77-93
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• 1999

This study is aiming at identifying the foreward and backward lingkage effects of the farm land base development project. Korean Government has continuously carried out farmland base development projets including the integrated agricultural development projects. large and medium scale irrigation projects and the comprehensive development of the four big river basin including tidal land reclamation and estuary dam construction for the all weather farming since 1962. the starting year of the five year economic development plans. Consequently the irrigation rate of paddy fields in Korea reached to 75% in 1998 and to escalate the irrigation rate, the Government had procured heavy investment fund from IBRD. IMF and OECF etc. To cope with the agricultural problems like trade liberalization in accordance with WTO policy, the government has tried to solve such problems as new farmland base development policy, preservation of the farmland and expansion of farmland to meet self-sufficiency of foods in the future. Especially, farmland base development projects have been challanged to environmental and ecological problems in evaluating economic benefits and costs where the value of non-market goods have not been included in those. Up to data, in evaluating benefits and costs of the projects, farmland base development projects have been confined to direct incremental value of farm products and it's related costs. Therefore the projects'efficiency as a decision making criteria has shown the low level of economic efficiencies. In estimating economic efficiencies including Leontiefs input-output analysis of the projects could not be founded in Korea at present. Accordingly this study is aimed at achieving and identifying the following objectives. (1) To identify the problems related to the financial supports of the Government in implementing the proposed projects. (2) To estimated backward and foreward linkage effects of the proposed project from the view point of national economy as a whole. To achieve the objectives, Hwangrak benefited area with reservoir which is located in Seosan-haemi Disticts, Chungnam Province were selected as a case study. The main results of the study are summarized as follows : a. The present value of investment and O & M cost were amounted to 3,510million won and the present value of the value added in related industries was estimated at 5.913million won for the period of economic life of 70 years. b. The total discounted value of farm products in the concerned industries derived by the project was estimated at 10,495million won and the foreward and backward linkage effects of the project were amounted to 6,760 and 5,126million won respectively. c. The total number of employment opportunities derived from the related industries for the period of project life were 3,136 man/year. d. Farmland base development projects were showed that the backward linkage effects estimated by index of the sensitivity dispersion were larger than the forward linkage effect estimated by index of the power of dispersion. On the other hand, the forward linkage effect of rice production value during project life was larger than the backward linkage effect e. The rate of creation of new job opportunity by means of implementing civil engineering works were shown high in itself rather than any other fields. and the linkage effects of production of the project investment were mainly derived from the metal and non-metal fields. f. According to the industrial linkage effect analysis, farmland base development projects were identified economically feasible from the view point of national economy as a whole even though the economic efficiencies of the project was outstandingly decreased owing to delaying construction period and increasing project costs.

• Applied Biological Chemistry
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• 제34권3호
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• pp.235-241
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• 1991

김치에 사용되는 여러가지 향신료가 발효 숙성에 미치는 영향을 알기 위하여 주재료인 배추에 향신료의 종류와 배합량을 달리하여 담근 김치의 숙성중 발효속도, pH, 적정산도, 환원당 함량 및 ascorbic acid 함량의 변화를 측정한 결과는 다음과 같다. 절인 배추의 염농도를 3%로 조절한 다음 고추가루, 마늘 및 청파는 1, 2, 3%를, 생강은 0.5, 1.0, 1.5%를 각각 첨가한 시험에서 숙성 30시간 경부터 고추가루 2% 첨가구의 발효속도는 높아져 최고치를 보이다가 낮아졌으나 3% 첨가구는 최대값을 보이지 않고 계속 증가하였다. 고추가루 첨가구의 환원당함량과 적정 산도는 높았으며, pH는 약간 낮게 나타났다. 마늘 첨가구의 발효속도는 숙성 12시간부터 높게 나타났고, pH 및 환원당은 같은 시간에 감소하기 시작하였으나 적정산도는 높아졌다. Ascorbic acid는 숙성 6시간 후 증가하여 최고치를 나타내는 18시간경에는 담금 시보다 높았다. 청파 및 생강은 첨가 효과가 크게 나타나지 않았다.

• 한국구조물진단유지관리공학회 논문집
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• 제14권3호
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• pp.186-195
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• 2010

본 논문은 SC합성보에 정착구의 높이, 새들의 형태, 가력시점을 변수로 하여 비부착 포스트텐션 보강을 하고 휨실험을 통해 보강방법을 평가하여 적절한 보강방법을 제시하고자 하엿다. 실험결과 보강 전 SC합성보의 최대내력은 실험값/이론값이 0.97로 나타났으나 보강 후는 1.00~1.21로 나타나 보강효과를 확인할 수 있었다. 변위 및 변형률 분석결과 정착구의 높이 및 가력시점에 상관없이 보강 후 중립축에 정착구를 설치한 D120계열 실험체가 최대하중이후 급격한 하중저하 없이 변위가 지속적으로 증가하며 각 부분의 변형률도 비교적 적게 나타나는 안정적인 거동을 했다. 보강효과면에서 선 가력 후 보강한 SCR-UD120실험체가 보강 전 SC합성보에 비해 최대내력이 1.72배 증가하여 가장 우수한 것으로 나타났다.

• Journal of Acupuncture Research
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• 제27권4호
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• pp.239-245
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• 2010

Objectives : The aim of this study is to evaluate the effect of cervical Hyeopcheok(Jiaji) point for neck pain. Methods : The twenty-nine patients who feel neck pain, are chosen from chart review, received acupuncture treatment on cervical Hyeopcheok(Jiaji) point. The evaulation of progress was checked by NDI(neck disability index), and VAS(visual analog scale). Data were analyzed by Friedman two way analysis of variance and Wilcoxon matched pairs signed rank test. Results : NDI value(mean${\pm}$SD) was $17.76{\pm}8.26$(n=29) at the first visit, $13.41{\pm}8.04$(n=29) at 3days after treatment, $10.85{\pm}8.46$(n=26) at 5days, $11.00{\pm}7.80$(n=13) at 9days, $7.22{\pm}4.76$(n=9) at 15days, $3.86{\pm}4.06$(n=7) at 20days, and $3.33{\pm}3.78$(n=6) at 30days. VAS value(mean${\pm}$SD) was $4.07{\pm}1.33$(n=29) at the first visit, $12.97{\pm}1.05$(n=29) at 3days after treatment, $2.15{\pm}1.12$(n=26) at 5days, $2.15{\pm}0.99$(n=13) at 9days, $1.56{\pm}0.73$(n=9) at 15days, $1.29{\pm}0.49$(n=7) at 20days, and $0.83{\pm}0.41$(n=6) at 30days. The value of NDI and VAS gradually decreased. Repeated measurement results(the difference between the first visit and each measurement day) and the difference between before and after the interval(except between 5 and 9days, between 20 and 25days) were statistically significant. Conclusions : This result was shown that treatment of cervical Hyeopcheok(Jiaji) acupuncture point for neck pain can be effective. Further systematic research will be needed.

• 한국식품위생안전성학회지
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• 제10권2호
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• pp.97-102
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• 1995

For improved preservation of boiled-dried anchovies, the current preservation method of corrugated-cardboard box packaging and freezing below -18$^{\circ}C$ was compared to the nylon/polyethylene(NY/PE) packaging along with cooling temperature ranging from 5$^{\circ}C$ to 1$0^{\circ}C$ as well as ambient condition for eight months by determining physicochemical quality of stored samples. Lipid oxidation of stored anchovies and their browning increased with storage time. The phenomenon was delayed under the conditions of lower temperature and air-tight packaging. As quality-indicative criteria of stored anchovies, carbonyl value(r=-0.989), browning (r=-0.949) and color a value(r=-0.989), browning(r=-0.965), Hunter's color b value(r=-0.949) and color a value(r=-0.940) showed a highly-negative correlations with organoleptic qualities of the samples. Based on the above results, air-tight packaging in a laminated film and subsequent storage at cooling temperature was found to be a possible alternative to the current freezing-storage of boiled-dried anchovies from the physicochemical point of view.

• Journal of Astronomy and Space Sciences
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• 제30권4호
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• pp.321-326
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• 2013

The modulation transfer function (MTF) is a widely used indicator in assessments of remote-sensing image quality. This MTF method is also used to restore information to a standard value to compensate for image degradation caused by atmospheric or satellite jitter effects. In this study, we evaluated MTF values as an image quality indicator for the Geostationary Ocean Color Imager (GOCI). GOCI was launched in 2010 to monitor the ocean and coastal areas of the Korean peninsula. We evaluated in-orbit MTF value based on the GOCI image having a 500-m spatial resolution in the first time. The pulse method was selected to estimate a point spread function (PSF) with an optimal natural target such as a Seamangeum Seawall. Finally, image restoration was performed with a Wiener filter (WF) to calculate the PSF value required for the optimal regularization parameter. After application of the WF to the target image, MTF value is improved 35.06%, and the compensated image shows more sharpness comparing with the original image.