• Title/Summary/Keyword: Local Search Method

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Parallel Optimal Power Flow Using PC Clustering (PC 클러스터링을 이용한 병렬 최적조류계산에 관한 연구)

  • Kim, Cheol-Hong;Mun, Kyeong-Jun;Kim, Hyung-Su;Park, J.H.;Kim, Jin-Ho;Lee, Hwa-Seok
    • Proceedings of the KIEE Conference
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    • 2004.11b
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    • pp.190-193
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    • 2004
  • Optimal Power Flow (OPF) is becoming more and more important in the deregulation environment of power pool and there is an urgent need of faster solution technique for on-line application. So this paper presents parallel genetic algorithm-tap search for the solution of the OPF. The control variables modeled unit active power outputs, generator-bus voltage magnitudes and transformer-tap settings. A number of functional operating constraints, such as branch flow limits, load bus boltage magnitude limits and generator reactive capabilities are included as penalties in the fitness function. In parallel GA-TS, GA operators are executed for each process. If best fitness of the GA is not changed for several generations, TS operators are executed for the upper three populations to enhance the local searching capabilities. With migration operation, best string of each node is transferred to the neighboring node after predetermined iterations are executed. For parallel computing, we developed a PC-cluster system consisting of 8 PCs. Each PC employs the 2 GHz Pentium IV CPU and is connected with others through ethernet switch based fast ethernet. To show the usefulness of the proposed method, developed algorithm has been tested and compared on an IEEE 30-bus system in the reference paper. From the simulation results, we can find that the proposed algorithm is efficient for the OPF.

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Definitive Closure of the Tracheoesophageal Puncture Site after Oncologic Laryngectomy: A Systematic Review and Meta-Analysis

  • Escandon, Joseph M.;Mohammad, Arbab;Mathews, Saumya;Bustos, Valeria P.;Santamaria, Eric;Ciudad, Pedro;Chen, Hung-Chi;Langstein, Howard N.;Manrique, Oscar J.
    • Archives of Plastic Surgery
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    • v.49 no.5
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    • pp.617-632
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    • 2022
  • Tracheoesophageal puncture (TEP) and voice prosthesis insertion following laryngectomy may fail to form an adequate seal. When spontaneous closure of the fistula tract does not occur after conservative measures, surgical closure is required. The purpose of this study was to summarize the available evidence on surgical methods for TEP site closure. A comprehensive search across PubMed, Web of Science, SCOPUS, and Cochrane was performed to identify studies describing surgical techniques, outcomes, and complications for TEP closure. We evaluated the rate of unsuccessful TEP closure after surgical management. A meta-analysis with a random-effect method was performed. Thirty-four studies reporting on 144 patients satisfied inclusion criteria. The overall incidence of an unsuccessful TEP surgical closure was 6% (95% confidence interval [CI] 1-13%). Subgroup analysis showed an unsuccessful TEP closure rate for silicone button of 8% (95% CI < 1-43%), 7% (95% CI < 1-34%) for dermal graft interposition, < 1% (95% CI < 1-37%) for radial forearm free flap, < 1% (95% CI < 1-52%) for ligation of the fistula, 17% (95% CI < 1-64%) for interposition of a deltopectoral flap, 9% (95% CI < 1-28%) for primary closure, and 2% (95% CI < 1-20%) for interposition of a sternocleidomastoid muscle flap. Critical assessment of the reconstructive modality should take into consideration previous history of surgery or radiotherapy. Nonirradiated fields and small defects may benefit from fistula excision and tracheal and esophageal multilayer closure. In cases of previous radiotherapy, local flaps or free tissue transfer yield high successful TEP closure rates. Depending on the defect size, sternocleidomastoid muscle flap or fasciocutaneous free flaps are optimal alternatives.

A multi-layer approach to DN 50 electric valve fault diagnosis using shallow-deep intelligent models

  • Liu, Yong-kuo;Zhou, Wen;Ayodeji, Abiodun;Zhou, Xin-qiu;Peng, Min-jun;Chao, Nan
    • Nuclear Engineering and Technology
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    • v.53 no.1
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    • pp.148-163
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    • 2021
  • Timely fault identification is important for safe and reliable operation of the electric valve system. Many research works have utilized different data-driven approach for fault diagnosis in complex systems. However, they do not consider specific characteristics of critical control components such as electric valves. This work presents an integrated shallow-deep fault diagnostic model, developed based on signals extracted from DN50 electric valve. First, the local optimal issue of particle swarm optimization algorithm is solved by optimizing the weight search capability, the particle speed, and position update strategy. Then, to develop a shallow diagnostic model, the modified particle swarm algorithm is combined with support vector machine to form a hybrid improved particle swarm-support vector machine (IPs-SVM). To decouple the influence of the background noise, the wavelet packet transform method is used to reconstruct the vibration signal. Thereafter, the IPs-SVM is used to classify phase imbalance and damaged valve faults, and the performance was evaluated against other models developed using the conventional SVM and particle swarm optimized SVM. Secondly, three different deep belief network (DBN) models are developed, using different acoustic signal structures: raw signal, wavelet transformed signal and time-series (sequential) signal. The models are developed to estimate internal leakage sizes in the electric valve. The predictive performance of the DBN and the evaluation results of the proposed IPs-SVM are also presented in this paper.

A study on modularization of public data that can be used universally in the field of big data education (빅데이터교육 현장에서 범용적으로 활용 가능한 공공데이터 모듈화 연구)

  • Su-Youn Choi;Jong-Youel Park
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.655-661
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    • 2023
  • Big data, an important element of the 4th industrial revolution, is actively opening public data in public institutions and local governments. In the public data portal, everyone can conveniently search for data and check related data, but only those in ICT-related fields are using public data. Although data held by public institutions is open to citizens, it is difficult for anyone to easily utilize public data to develop applications. In this paper, data provided in open API format from public data portals has XML and JSON formats. In this study, we are a method of modularizing public data in XML format into a part that can be easily developed by linking it to a GUI interface. Based on the necessary public data, we propose a way to easily develop mobile programs and promote the use of public data.

A Study on Sound Design to Improve Regional Image -Focused on the Jeonju Area- (지역이미지 활성을 위한 사운드 디자인에 관한 연구)

  • Kim, Mee-Shuk;Chung, Sung-Whan;Hyoun, Sung-Eun
    • Science of Emotion and Sensibility
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    • v.10 no.4
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    • pp.613-622
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    • 2007
  • Recently, sound design is being made by corporations for the production as well as for marketing and web with consideration of image of productions and attributes to improve corporational image through the design of melody which would remain in users. And sound is becoming an important factor to establish the identity of each area such as life environment and public facilities. At present, our local governments are promoting active business like as CIP to improve urban image but there is a limit to establish identity as the result of its partial focus on visual sense or insufficient recognition about it. Jeonju, the place of sound, has many festivals and great meetings related with sound but it has not identity in the sense of sound. So the purpose of this study is to suggest the condition of sound which has the trait of Jeonju and to provide data for the trait to be used as a necessary element to establish identity in order to activate regional image. For the method of research, sampling Korean beautiful 100 sounds among the natural sounds of residents. most favorite as the samples of sound to search the sound of regional image. Selecting favorite samples among them and analyzed the factors through the questionnaire on the image of adjective in each sample. As the result of analysis, it has been shown that the factor of sound to reveal trait of Jeonju is the image of bright, delight, and cozy with consideration of harmony, dynamics, contrast, and culture. For this study is to provide data so it can be used to actively establish and identify the local image.

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Invariant Classification and Detection for Cloth Searching (의류 검색용 회전 및 스케일 불변 이미지 분류 및 검색 기술)

  • Hwang, Inseong;Cho, Beobkeun;Jeon, Seungwoo;Choe, Yunsik
    • Journal of Broadcast Engineering
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    • v.19 no.3
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    • pp.396-404
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    • 2014
  • The field of searching clothing, which is very difficult due to the nature of the informal sector, has been in an effort to reduce the recognition error and computational complexity. However, there is no concrete examples of the whole progress of learning and recognizing for cloth, and the related technologies are still showing many limitations. In this paper, the whole process including identifying both the person and cloth in an image and analyzing both its color and texture pattern is specifically shown for classification. Especially, deformable search descriptor, LBPROT_35 is proposed for identifying the pattern of clothing. The proposed method is scale and rotation invariant, so we can obtain even higher detection rate even though the scale and angle of the image changes. In addition, the color classifier with the color space quantization is proposed not to loose color similarity. In simulation, we build database by training a total of 810 images from the clothing images on the internet, and test some of them. As a result, the proposed method shows a good performance as it has 94.4% matching rate while the former Dense-SIFT method has 63.9%.

Scheduling of Parallel Offset Printing Process for Packaging Printing (패키징 인쇄를 위한 병렬 오프셋 인쇄 공정의 스케줄링)

  • Jaekyeong, Moon;Hyunchul, Tae
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.28 no.3
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    • pp.183-192
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    • 2022
  • With the growth of the packaging industry, demand on the packaging printing comes in various forms. Customers' orders are diversifying and the standards for quality are increasing. Offset printing is mainly used in the packaging printing since it is easy to print in large quantities. However, productivity of the offset printing decreases when printing various order. This is because it takes time to change colors for each printing unit. Therefore, scheduling that minimizes the color replacement time and shortens the overall makespan is required. By the existing manual method based on workers' experience or intuition, scheduling results may vary for workers and this uncertainty increase the production cost. In this study, we propose an automated scheduling method of parallel offset printing process for packaging printing. We decompose the original problem into assigning and sequencing orders, and ink arrangement for printing problems. Vehicle routing problem and assignment problem are applied to each part. Mixed integer programming is used to model the problem mathematically. But it needs a lot of computational time to solve as the size of the problem grows. So guided local search algorithm is used to solve the problem. Through actual data experiments, we reviewed our method's applicability and role in the field.

Numerical studies of information about elastic parameter sets in non-linear elastic wavefield inversion schemes (비선형 탄성파 파동장 역산 방법에서 탄성파 변수 세트에 관한 정보의 수치적 연구)

  • Sakai, Akio
    • Geophysics and Geophysical Exploration
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    • v.10 no.1
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    • pp.1-18
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    • 2007
  • Non-linear elastic wavefield inversion is a powerful method for estimating elastic parameters for physical constraints that determine subsurface rock and properties. Here, I introduce six elastic-wave velocity models by reconstructing elastic-wave velocity variations from real data and a 2D elastic-wave velocity model. Reflection seismic data information is often decoupled into short and long wavelength components. The local search method has difficulty in estimating the longer wavelength velocity if the starting model is far from the true model, and source frequencies are then changed from lower to higher bands (as in the 'frequency-cascade scheme') to estimate model elastic parameters. Elastic parameters are inverted at each inversion step ('simultaneous mode') with a starting model of linear P- and S-wave velocity trends with depth. Elastic parameters are also derived by inversion in three other modes - using a P- and S-wave velocity basis $('V_P\;V_S\;mode')$; P-impedance and Poisson's ratio basis $('I_P\;Poisson\;mode')$; and P- and S-impedance $('I_P\;I_S\;mode')$. Density values are updated at each elastic inversion step under three assumptions in each mode. By evaluating the accuracy of the inversion for each parameter set for elastic models, it can be concluded that there is no specific difference between the inversion results for the $V_P\;V_S$ mode and the $I_P$ Poisson mode. The same conclusion is expected for the $I_P\;I_S$ mode, too. This gives us a sound basis for full wavelength elastic wavefield inversion.

A Qualitative Study on the Community Participation Experiences of Married Immigrant Women in Rural Areas (농촌지역 결혼이주여성의 지역사회활동 참여경험에 관한 질적 연구)

  • Lee, Hyoung-Ha
    • Korean Journal of Social Welfare
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    • v.62 no.3
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    • pp.219-245
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    • 2010
  • The objective of this study is to identify the community living experiences of married immigrant women in rural areas. For this purpose, we conducted qualitative research by sampling 14 married immigrant women who had lived in Korea for over three years by having in depth interviews with them. This study employed the grounded theory method suggested by Strauss and Corbin(1998). When raw data from in depth interviews with the participants were processed by open coding through the continuous comparison method with theoretical sensitivity, a total of 13 categories, 27 sub.categories, and 71 concepts were extracted. In case of axial coding, according to the results of analyzing through the paradigm procedure, the causal conditions for the community living experiences of married immigrant women in rural areas were 'Uncertain start' and 'Confront practical problems,' and the central phenomenon was 'Search for existence to participate in community activities.' Contextual conditions affecting the phenomenon was 'Regret international marriage,' 'Experience conflicts,' and 'Look with negative prejudices,' 'Overcome the actual' and action/interaction strategies were 'Look for a breakthrough of life' and 'Manage to acceptance.' Intervening conditions for promoting or suppressing the action/interaction strategies for the central phenomenon were 'Social support system' and 'local limitations,' and as a result, the community living experiences of married immigrant women in rural areas appeared to 'Prepare the future,' 'Hope continuous social activities,' and 'Expect public support systems.'

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Molecular Analysis of Pathogenic Molds Isolated from Clinical Specimen (임상검체에서 분리된 병원성 사상균의 분자생물학적 분석)

  • Lee, Jang Ho;Kwon, Kye Chul;Koo, Sun Hoe
    • Korean Journal of Clinical Laboratory Science
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    • v.52 no.3
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    • pp.229-236
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    • 2020
  • Sixty-five molds isolated from clinical specimens were included in this study. All the isolates were molds that could be identified morphologically, strains that are difficult to identify because of morphological similarities, and strains that require species-level identification. PCR and direct sequencing were performed to target the internal transcribed spacer (ITS) region, the D1/D2 region, and the β-tubulin gene. Comparative sequence analysis using the GenBank database was performed using the basic local alignment search tool (BLAST) algorithm. The fungi identified morphologically to the genus level were 67%. Sequencing analysis was performed on 62 genera and species level of the 65 strains. Discrepancies were 14 (21.5%) of the 65 strains between the results of phenotypic and molecular identification. B. dermatitidis, T. marneffei, and G. argillacea were identified for the first time in Korea using the DNA sequencing method. Morphological identification is a very useful method in terms of the reporting time and costs in cases of frequently isolated and rapid growth, such as Aspergillus. When molecular methods are employed, the cost and clinical significance should be considered. On the other hand, the molecular identification of molds can provide fast and accurate results.