• Title/Summary/Keyword: Combined weights

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A Study on the Optimal Operation According to Appropriate PCS and Battery Capacity Estimation of PV-BESS System (PV-BESS 시스템의 적정 PCS, 배터리용량 산정에 따른 최적 운영에 관한 연구)

  • Choi, Yun Suk;Na, Seung You
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.9
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    • pp.1174-1180
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    • 2018
  • In December 2017, the government announced plans to increase the current proportion of renewable energy from 7% to 20% by 2030 through a plan called the Renewable Energy 3020 Implementation Plan. Therefore, the demand for installation of photovoltaic(PV), wind turbine(WT) and battery energy storage system(BESS) is expected to increase. In particular, the system combined with energy storage system(ESS) is expected to take up a large portion since PV and WT can receive high renewable energy certificates(REC) weights when combined with ESS. In this study, we calculate the optimal capacity of the power conditioning system(PCS) and the BESS by comparing the economical efficiency and maximize the efficiency of the PV-BESS system in which the PV and the BESS are connected. By analyzing the system marginal price(SMP) and REC, it maximize profits through application of REC weight 5.0 and optimal charge-discharge scheduling according to the SMP changes.

An Efficient Positioning Method for Multi-GNSS with Multi-SBAS

  • Park, Kwi Woo;Cho, MinGyou;Park, Chansik
    • Journal of Positioning, Navigation, and Timing
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    • v.7 no.4
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    • pp.245-253
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    • 2018
  • The current SBAS service does not provide a method to integrate multiple SBAS corrections. This paper proposes a positioning method to effectively integrate multiple SBAS and multiple GNSS. In the method, the final position is obtained by the weighted sum of the positions obtained from the combination of GNSS and SBAS. Since each position is independently computed and combined using flexible weights, it has a simple structure that can easily cope with various environments. In order to verify the operation and performance of the proposed method, raw measurements of GNSS and SBAS were collected using commercial receivers. The experiments using real signals show that the combined use of two SBAS corrections was more accurate by 0.05~0.4m(2dRMS) than using only one SBAS correction. To improve the position accuracy, this paper considered the integration of multi-GNSS and multi-SBAS, which was not found in other existing studies. The proposed method is expected to be a core technology for designing multi-GNSS navigation receivers considering multi-SBAS corrections. The importance of the method will be increased as KPS and KASS also available in near future.

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.

A Folksonomy Ranking Framework: A Semantic Graph-based Approach (폭소노미 사이트를 위한 랭킹 프레임워크 설계: 시맨틱 그래프기반 접근)

  • Park, Hyun-Jung;Rho, Sang-Kyu
    • Asia pacific journal of information systems
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    • v.21 no.2
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    • pp.89-116
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    • 2011
  • In collaborative tagging systems such as Delicious.com and Flickr.com, users assign keywords or tags to their uploaded resources, such as bookmarks and pictures, for their future use or sharing purposes. The collection of resources and tags generated by a user is called a personomy, and the collection of all personomies constitutes the folksonomy. The most significant need of the folksonomy users Is to efficiently find useful resources or experts on specific topics. An excellent ranking algorithm would assign higher ranking to more useful resources or experts. What resources are considered useful In a folksonomic system? Does a standard superior to frequency or freshness exist? The resource recommended by more users with mere expertise should be worthy of attention. This ranking paradigm can be implemented through a graph-based ranking algorithm. Two well-known representatives of such a paradigm are Page Rank by Google and HITS(Hypertext Induced Topic Selection) by Kleinberg. Both Page Rank and HITS assign a higher evaluation score to pages linked to more higher-scored pages. HITS differs from PageRank in that it utilizes two kinds of scores: authority and hub scores. The ranking objects of these pages are limited to Web pages, whereas the ranking objects of a folksonomic system are somewhat heterogeneous(i.e., users, resources, and tags). Therefore, uniform application of the voting notion of PageRank and HITS based on the links to a folksonomy would be unreasonable, In a folksonomic system, each link corresponding to a property can have an opposite direction, depending on whether the property is an active or a passive voice. The current research stems from the Idea that a graph-based ranking algorithm could be applied to the folksonomic system using the concept of mutual Interactions between entitles, rather than the voting notion of PageRank or HITS. The concept of mutual interactions, proposed for ranking the Semantic Web resources, enables the calculation of importance scores of various resources unaffected by link directions. The weights of a property representing the mutual interaction between classes are assigned depending on the relative significance of the property to the resource importance of each class. This class-oriented approach is based on the fact that, in the Semantic Web, there are many heterogeneous classes; thus, applying a different appraisal standard for each class is more reasonable. This is similar to the evaluation method of humans, where different items are assigned specific weights, which are then summed up to determine the weighted average. We can check for missing properties more easily with this approach than with other predicate-oriented approaches. A user of a tagging system usually assigns more than one tags to the same resource, and there can be more than one tags with the same subjectivity and objectivity. In the case that many users assign similar tags to the same resource, grading the users differently depending on the assignment order becomes necessary. This idea comes from the studies in psychology wherein expertise involves the ability to select the most relevant information for achieving a goal. An expert should be someone who not only has a large collection of documents annotated with a particular tag, but also tends to add documents of high quality to his/her collections. Such documents are identified by the number, as well as the expertise, of users who have the same documents in their collections. In other words, there is a relationship of mutual reinforcement between the expertise of a user and the quality of a document. In addition, there is a need to rank entities related more closely to a certain entity. Considering the property of social media that ensures the popularity of a topic is temporary, recent data should have more weight than old data. We propose a comprehensive folksonomy ranking framework in which all these considerations are dealt with and that can be easily customized to each folksonomy site for ranking purposes. To examine the validity of our ranking algorithm and show the mechanism of adjusting property, time, and expertise weights, we first use a dataset designed for analyzing the effect of each ranking factor independently. We then show the ranking results of a real folksonomy site, with the ranking factors combined. Because the ground truth of a given dataset is not known when it comes to ranking, we inject simulated data whose ranking results can be predicted into the real dataset and compare the ranking results of our algorithm with that of a previous HITS-based algorithm. Our semantic ranking algorithm based on the concept of mutual interaction seems to be preferable to the HITS-based algorithm as a flexible folksonomy ranking framework. Some concrete points of difference are as follows. First, with the time concept applied to the property weights, our algorithm shows superior performance in lowering the scores of older data and raising the scores of newer data. Second, applying the time concept to the expertise weights, as well as to the property weights, our algorithm controls the conflicting influence of expertise weights and enhances overall consistency of time-valued ranking. The expertise weights of the previous study can act as an obstacle to the time-valued ranking because the number of followers increases as time goes on. Third, many new properties and classes can be included in our framework. The previous HITS-based algorithm, based on the voting notion, loses ground in the situation where the domain consists of more than two classes, or where other important properties, such as "sent through twitter" or "registered as a friend," are added to the domain. Forth, there is a big difference in the calculation time and memory use between the two kinds of algorithms. While the matrix multiplication of two matrices, has to be executed twice for the previous HITS-based algorithm, this is unnecessary with our algorithm. In our ranking framework, various folksonomy ranking policies can be expressed with the ranking factors combined and our approach can work, even if the folksonomy site is not implemented with Semantic Web languages. Above all, the time weight proposed in this paper will be applicable to various domains, including social media, where time value is considered important.

The Estrogenicity and Reproductive Toxicity by Combined Treatment of Bisphenol A and Benzyl butyl phthalate during Gestation, Lactation Period in Rats

  • Hwang, Seong-Hee;Kim, Jeong-Hyun;Kang, Hee-Joo;Kim, Hyun-Soo;Kim, Kyong-Tae;Kim, Pan-Gyi
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2004.06a
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    • pp.185-187
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    • 2004
  • The co-administration of BPA and BBP induced slow weight gain compared with single administration in dams. Also, such mixture induced low neonatal body weights in next generation. The dams treated with BPA and BBP showed significant organ weight changes in liver, spleen exposed during lactational periods. But the dams exposed during lactational periods showed significant organ weight changes not only in liver, spleen but also in kidney, uterus and ovary. The F1 female rats exposed during lactation periods showed significant organ weight changes in liver, spleen, ovary. The F1 male rats showed significant organ weight changes in liver, kidney, epididymis, vesicular glands, prostate. However no clear synergistic effects of BPA and BBP could be found. Estrogen receptor ${\alpha}$ expression by BPA and BBP in the uterus(dam, F1 female) and testis(F1 male) were studied. There was no significant different $ER{\alpha}$ expression pattern between control and treated groups. But $ER{\alpha}$ expression were increased in F1 male testis and female uterus. F1 male showed distinct $ER{\alpha}$ expression, especially in the group of lactational combined exposure. Synergistic $ER{\alpha}$ expression was found by combined treatment of BPA and BBP.

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Effect of Polyherbal Feed Supplement "Growell" during Induced Aflatoxicosis, Ochratoxicosis and Combined Mycotoxicoses in Broilers

  • Kalorey, D.R.;Kurkure, N.V.;Ramgaonkar, J.S.;Sakhare, P.S.;Warke, Shubhangi;Nigot, N.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.3
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    • pp.375-383
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    • 2005
  • An experiment was conducted to study the protective role of polyherbal feed supplement (Growell) during induced mycotoxicosis in broilers. A total of 240 Vencobb broilers were divided at day old stage into eight equal groups. Group A served as control and was given plain feed, group B, D, F and H were given Growell at 0.35 g/kg of feed. Group C, D, G and H were given dietary aflatoxin $B_1$ at 0.2 ppm and groups E, F, G and H were given ochratoxin A at 0.2 ppm in feed to study effect of Growell on individual aflatoxicosis, ochratoxicosis and combined mycotoxicosis of broilers. The chicks were given their respective feeds from 1st day to 6th week of age and were vaccinated at 7th and 28th day of age with Lasota strain of Newcastle disease virus. There was no statistically significant effect of mycotoxins individually or in combination on body weight of broilers. However, body weights were highest in group B and lowest in co-mycotoxicated group G. Feed conversion ratio was best in group B followed by A, D, F, E, H and G. Significant improvement in haemoglobin values was observed in broilers due to feeding of Growell in ochratoxin and co-mycotoxicated groups. There was no significant effect of mycotoxin treatment on PCV, TEC and TLC of broilers. Due to single and combined mycotoxicosis, there was reduction in serum total protein, albumin, cholesterol and triglyceride and rise in alkaline phosphatase, creatinine and uric acid levels. Supplementation of diets with Growell reduced the alterations induced due to mycotoxins. There was a significant rise in per cent organ weight of liver and reduction of that of spleen, bursa of Fabricius and thymus of broilers fed mycotoxins. Protection from alteration in per cent organ weight of these organ by supplementation of Growell was recorded. The observed impaired immune response and histopathological changes in liver, kidney, spleen, bursa of Fabricius and thymus of broilers given mycotoxins were protected by supplementation of Growell.

Effect of Combining Wood Flakes and Polypropylene-net Flakes on Thickness Swelling and Bending Properties of Sawdust Board (목질(木質)플레이크와 폴리프로필렌망(網)플레이크 구성(構成)이 톱밥보오드의 팽창성(膨脹性)과 휨성질(性質)에 미치는 영향(影響))

  • Lee, Phil Woo;Eom, Young Geun;Oh, Sei Chang;Chung, In Ju
    • Journal of Korean Society of Forest Science
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    • v.77 no.2
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    • pp.252-257
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    • 1988
  • This study was carried out to investigate the physical and mechanical properties of sawdust boards combined with sycamore and polypropylene-net flakes. Both the sycamore and polypropylene-net flakes were adjusted to the sizes of $1.0{\times}1.0$, $1.0{\times}2.0$, and $1.5{\times}1.5cm^2$ and these flakes were mixed at 1, 2, 3, and 4% levels based on ovendry weights of sawdusts, respectively. The results obtained in this study were summarized as follows : 1. Thickness swellings of sawdust boards combined with sycamore flakes decreased with the increase of mixture levels and similar effects were also recognized in combination with polypropylene-net flakes. 2. Moduli of rupture both in sawdust boards combined with sycamore and polypropylene-net flakes increased with the increase of their mixture levels, and sawdust boards combined with sycamore flakes of $1.0{\times}2.0cm^2$ size and polypropylene-net flakes of $1.5{\times}1.5cm^2$ size showed higher moduli of rupture than control boards. 3. Moduli of elasticity both in sawdust hoards combined with sycamore and polypropylene-net flakes increased with the increase of their mixture levels as in moduli of rupture. 4. The physical and mechanical properties of sawdust boards combined with sycamore and polypropylene-net flakes were mainly dependent on aspect ratio of sycamore flakes and size of polypropylene-net flakes respectively, and these properties were improved with the respective increase of aspect ratio and size.

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The anti-climacterium effects of red clover dry extracts combined with pomegranate concentration powder in ovariectomized rats

  • Kim, Kyung Hu;Kang, Su Jin;Choi, Beom Rak;Kim, Seung Hee;Yi, Hae Yeon;Kim, Dong Chul;Choi, Seong Hun;Han, Chang Hyun;Park, Soo Jin;Song, Chang Hyun;Ku, Sae Kwang;Lee, Young Joon
    • Journal of Society of Preventive Korean Medicine
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    • v.18 no.2
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    • pp.133-145
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    • 2014
  • Objective : In this study, the addition of dried pomegranate concentrate powder (PCP) was affected the anti-climacterium activity of red clover dry extracts (RC) in ovariectomized (OVX) rats. Materials and methods : After bilateral OVX surgery, RC 40 mg/kg, PCP 20 mg/kg and RC:PCP 2:1 mixture (g/g) 120, 60 and 30 mg/kg (of body weight) were orally administered, once a day for 84 days, and then the changes on the serum estradiol levels, abdominal fat pad and uterus weights were observed for estrogenic effects. In addition, liver weights, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were also evaluated for hepatoprotective effects, and serum total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglyceride (TG) levels were monitored for hypolipidemic effects. Results : As a result of OVX, the estrogen-deficient climacterium symptoms, increments of abdominal fat pad weights, serum AST, ALT, TC, LDL and TG levels with decrease of uterus and liver weights, serum estradiol levels, were demonstrated. However, these estrogen-deficient climacterium symptoms induced by bilateral OVX in rats were significantly inhibited by continuous oral treatment of RC 40 mg/kg, PCP 20 mg/kg and RC:PCP 2:1 mixture (g/g) 120, 60 and 30 mg/kg, respectively. Conclusion : The results suggested that RC:PCP 2:1 mixtures synergistically increased the anti-climacterium effects of RC in OVX rats. It, therefore, is expected that RC:PCP 2:1 mixture will be promising as a new potent protective agents for relieving the climacterium symptoms.

Regrouping Service Sites: a Genetic Approach using a Voronoi Diagram (서비스 위치 그룹핑을 위한 보로노이 다이어그램 기반의 유전자알고리듬)

  • Seo, Jeong-Yeon;Park, Sang-Min;Jeong, In-Jae;Kim, Deok-Soo
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2005.05a
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    • pp.179-187
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    • 2005
  • In this paper, we consider the problem of regrouping a number of service sites into a smaller number of service sites called centers. Each service site is represented as a point in the plane and has an associated value of service demand. We aim to group the sites so that each group has the balanced service demand and the sum of distances from the sites in the group to their corresponding center is minimized. To solve this problem, we propose a hybrid genetic algorithm that is combined with Voronoi diagrams. We provide a variety of experimental results by changing the weights of the two factors: service demands and distances. Our hybrid algorithm finds better solutions in a shorter computation time in comparison with a pure genetic algorithm.

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Robust Map Building in Narrow Environments based on Combination of Sonar and IR Sensors (좁은 환경에서 초음파 및 적외선 센서를 융합한 강인한 지도작성)

  • Han, Hye-Min;Song, Jae-Bok
    • The Journal of Korea Robotics Society
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    • v.6 no.1
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    • pp.42-48
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    • 2011
  • It is very important for a mobile robot to recognize and model its environments for navigation. However, the grid map constructed by sonar sensors cannot accurately represent the environment, especially the narrow environment, due to the angular uncertainty of sonar data. Therefore, we propose a map building scheme which combines sonar sensors and IR sensors. The maps built by sonar sensors and IR sensors are combined with different weights which are determined by the degree of translational and rotational motion of a robot. To increase the effectiveness of sensor fusion, we also propose optimal sensor arrangement through various experiments. The experimental results show that the proposed method can represent the environment such as narrow corridor and open door more accurately than conventional sonar sensor-based map building methods.