• Title/Summary/Keyword: Global Minimum

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An Analysis of Accuracy for Submarine Topographic Information by Interpolation Method (보간기법에 따른 해저지형의 정확도 분석)

  • Kim Ga-Ya;Moon Doo-Youl;Seo Dong-Ju
    • Journal of Ocean Engineering and Technology
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    • v.20 no.3 s.70
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    • pp.67-76
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    • 2006
  • Three-dimensional information of submarine topography was acquired by assembling DGPS and Echo Sounder, which is mainly used in the marine survey. However, the features of submarine topography, derived according to mechanical data, were confirmed using human eyes. Because the dredging capacity using a submarine surveying data influences harbor public affairs, analysis and the process method of surveying data is a very special element in construction costs. In this study, information on submarine topography is acquired by assembling DGPS and Echo Sounder. Moreover, the dredging capacity in harbor public affairs has been analyzed by the interpolation method: inverse distance to a power, kriging, minimum curvature, nearest neighbor, and radial basis function. Also, utilization of DGPS and Echo Sounder method in calculation of the dredging capacity have been confirmed by comparing and analyzing the dredging capacity and the actual one, as per each interpolation. According to this comparison result, in the case of applying Radial basis function interpolation and Kriging, 3.94 % and 4.61 % of error rates have been shown, respectively. In the case of the study for application of the proper interpolation, as per characteristics of submarine topography, is preceded in calculation of the dredging capacity relevant to harbor public affairs, it is expected that more speedy and correct calculation for the dredging capacity can be made.

A Study on the Evaluation of Environmental Quality required in the Accreditation Program for Mental Health Facilities - Focus on the Mental Institutions Assessment of KOIHA (정신보건시설인증제에서 요구되는 시설환경 평가에 관한 연구 - 의료기관평가인증원의 정신의료기관평가를 중심으로)

  • Jung, Hee Boon;Kim, Uk
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.4
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    • pp.57-66
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    • 2016
  • Purpose: According to the trend of the global burden of disease, in the future our society is expected to face with gradually increasing problems related to mental health and the demand for the various types of quality mental health facilities. This study investigates whether the accreditation of Mental health facilities serves as a building evaluation tool, and contribute to environmental welfare of the mentally ill. Methods: The facility assessment items related to architectural design are extracted through the analysis about the accreditation program of KOIHA. Extracted items should review if they comply with the relevant regulations, and establish building design standard. Results: This study shows that the accreditation of KOIHA can certify psychiatric hospitals meet the legal requirements, the minimum standard of facilities. But it is not the evaluation of environmental quality. It is difficult to assess the quality of facility in terms of architectural design, because it has no specific standards or the level of assessment. Implications: The accreditation for mental health facilities should be able to provide the right and opportunity to choose a more quality facility for the customer. The introduction of a certification system for the evaluation of environmental quality is required in order to overcome the limitations of the accreditation of KOIHA. Development of design guidelines for mental health facilities that are the basis for certification should be also followed.

Pitch Period Detection Algorithm Using Rotation Transform of AMDF (AMDF의 회전변환을 이용한 피치 주기 검출 알고리즘)

  • Seo, Hyun-Soo;Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.1019-1022
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    • 2005
  • As recent information communication technology is rapidly developed, a lot of researches related to speech signal processing have been processed. So pitch period is applied as important factor to many application fields such as speech recognition, speaker identification, speech analysis and synthesis. Therefore, many algorithms related to pitch detection have been proposed in time domain and frequency domain and AMDF(average magnitude difference function) which is one of pitch detection algorithms in time domain chooses time interval from valley to valley as pitch period. But, in selection of valley point to detect pitch period, complexity of the algorithm is increased. So in this paper we proposed pitch detection algorithm using rotation transform of AMDF, that taking the global minimum valley point as pitch period and established a threshold about the phoneme in beginning portion, to exclude pitch period selection. and compared existing methods with proposed method through simulation.

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A Study on the Digital Electronic Compass by Integration of GPS Receiver and Earth's Magnetic Field Sensor (GPS수신기와 지자기센서 병행식 디지털 전자콤파스에 대한 연구)

  • Yun, Jae-Jun;Park, Gyei-Kark;Choi, Jo-Cheon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.168-172
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    • 2005
  • An autopilot system of a ship is very important for a safe and convenient navigation, which is realized with getting an azimuth data from a gyrocompass, a magnetic compass and a GPS(Global Positioning System) compass. Magnetic compass an azimuth error is generated by a vessel magnetism material such as steels. The magnetic pole is detected by the magnetic field sensor, it does not coincide with the true north, therefore, the detected azimuth data can not but accompany error. In this paper, in order to detect the minimum change of azimuth data which generates errors of azimuth information, a search algorithm using the Kalman Filtering method is utilized. The digital electronic compass is designed with the integration algorithm using the merits of an earth's magnetic field sensor and a GPS receiver.

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Development of Representative GCMs Selection Technique for Uncertainty in Climate Change Scenario (기후변화 시나리오 자료의 불확실성 고려를 위한 대표 GCM 선정기법 개발)

  • Jung, Imgook;Eum, Hyung-Il;Lee, Eun-Jeong;Park, Jihoon;Cho, Jaepil
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.5
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    • pp.149-162
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    • 2018
  • It is necessary to select the appropriate global climate model (GCM) to take into account the impacts of climate change on integrated water management. The objective of this study was to develop the selection technique of representative GCMs for uncertainty in climate change scenario. The selection technique which set priorities of GCMs consisted of two steps. First step was evaluating original GCMs by comparing with grid-based observational data for the past period. Second step was evaluating whether the statistical downscaled data reflect characteristics for the historical period. Spatial Disaggregation Quantile Delta Mapping (SDQDM), one of the statistical downscaling methods, was used for the downscaled data. The way of evaluating was using explanatory power, the stepwise ratio of the entire GCMs by Expert Team on Climate Change Detection and Indices (ETCCDI) basis. We used 26 GCMs based on CMIP5 data. The Representative Concentration Pathways (RCP) 4.5 and 8.5 scenarios were selected for this study. The period for evaluating reproducibility of historical period was 30 years from 1976 to 2005. Precipitation, maximum temperature, and minimum temperature were used as collected climate variables. As a result, we suggested representative 13 GCMs among 26 GCMs by using the selection technique developed in this research. Furthermore, this result can be utilized as a basic data for integrated water management.

A Study on the Robust Pitch Period Detection Algorithm in Noisy Environments (소음환경에 강인한 피치주기 검출 알고리즘에 관한 연구)

  • Seo Hyun-Soo;Bae Sang-Bum;Kim Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.481-484
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    • 2006
  • Pitch period detection algorithms are applied to various speech signal processing fields such as speech recognition, speaker identification, speech analysis and synthesis. Furthermore, many pitch detection algorithms of time and frequency domain have been studied until now. AMDF(average magnitude difference function) ,which is one of pitch period detection algorithms, chooses a time interval from the valley point to the valley point as the pitch period. AMDF has a fast computation capacity, but in selection of valley point to detect pitch period, complexity of the algorithm is increased. In order to apply pitch period detection algorithms to the real world, they have robust prosperities against generated noise in the subway environment etc. In this paper we proposed the modified AMDF algorithm which detects the global minimum valley point as the pitch period of speech signals and used speech signals of noisy environments as test signals.

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Influence of Temperature and Water Activity on Deleterious Fungi and Mycotoxin Production during Grain Storage

  • Mannaa, Mohamed;Kim, Ki Deok
    • Mycobiology
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    • v.45 no.4
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    • pp.240-254
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    • 2017
  • Cereal grains are the most important food source for humans. As the global population continues to grow exponentially, the need for the enhanced yield and minimal loss of agricultural crops, mainly cereal grains, is increasing. In general, harvested grains are stored for specific time periods to guarantee their continuous supply throughout the year. During storage, economic losses due to reduction in quality and quantity of grains can become very significant. Grain loss is usually the result of its deterioration due to fungal contamination that can occur from preharvest to postharvest stages. The deleterious fungi can be classified based on predominance at different stages of crop growth and harvest that are affected by environmental factors such as water activity ($a_w$) and eco-physiological requirements. These fungi include species such as those belonging to the genera Aspergillus and Penicillium that can produce mycotoxins harmful to animals and humans. The grain type and condition, environment, and biological factors can also influence the occurrence and predominance of mycotoxigenic fungi in stored grains. The main environmental factors influencing grain fungi and mycotoxins are temperature and $a_w$. This review discusses the effects of temperature and $a_w$ on fungal growth and mycotoxin production in stored grains. The focus is on the occurrence and optimum and minimum growth requirements for grain fungi and mycotoxin production. The environmental influence on aflatoxin production and hypothesized mechanisms of its molecular suppression in response to environmental changes are also discussed. In addition, the use of controlled or modified atmosphere as an environmentally safe alternative to harmful agricultural chemicals is discussed and recommended future research issues are highlighted.

Combining a HMM with a Genetic Algorithm for the Fault Diagnosis of Photovoltaic Inverters

  • Zheng, Hong;Wang, Ruoyin;Xu, Wencheng;Wang, Yifan;Zhu, Wen
    • Journal of Power Electronics
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    • v.17 no.4
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    • pp.1014-1026
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    • 2017
  • The traditional fault diagnosis method for photovoltaic (PV) inverters has a difficult time meeting the requirements of the current complex systems. Its main weakness lies in the study of nonlinear systems. In addition, its diagnosis time is long and its accuracy is low. To solve these problems, a hidden Markov model (HMM) is used that has unique advantages in terms of its training model and its recognition for diagnosing faults. However, the initial value of the HMM has a great influence on the model, and it is possible to achieve a local minimum in the training process. Therefore, a genetic algorithm is used to optimize the initial value and to achieve global optimization. In this paper, the HMM is combined with a genetic algorithm (GHMM) for PV inverter fault diagnosis. First Matlab is used to implement the genetic algorithm and to determine the optimal HMM initial value. Then a Baum-Welch algorithm is used for iterative training. Finally, a Viterbi algorithm is used for fault identification. Experimental results show that the correct PV inverter fault recognition rate by the HMM is about 10% higher than that of traditional methods. Using the GHMM, the correct recognition rate is further increased by approximately 13%, and the diagnosis time is greatly reduced. Therefore, the GHMM is faster and more accurate in diagnosing PV inverter faults.

Study on Improvement of Convergence in Harmony Search Algorithms (Harmony Search 알고리즘의 수렴성 개선에 관한 연구)

  • Lee, Sang-Kyung;Ko, Kwang-Enu;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.3
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    • pp.401-406
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    • 2011
  • In order to solve a complex optimization problem more efficiently than traditional approaches, various meta-heuristic algorithms such as genetic algorithm, ant-colony algorithm, and harmony search algorithm have been extensively researched. Compared with other meta-heuristic algorithm, harmony search algorithm shows a better result to resolve the complex optimization issues. Harmony search algorithm is inspired by the improvision process of musician for most suitable harmony. In general, the performance of harmony search algorithm is determined by the value of harmony memory considering rate, and pitch adjust rate. In this paper, modified harmony search algorithm is proposed in order to derive best harmony. If the optimal solution of a specific problem can not be found for a certain period of time, a part of original harmony memory is updated as the selected suitable harmonies. Experimental results using test function demonstrate that the updated harmony memory can induce the approximation of reliable optimal solution in the short iteration, because of a few change of fitness.

Theoretical Studies on Conformation of Cyclic Hexapeptides and Blocking for the Cation Transport by 5,5-diphenylhydantoin (고리형 헥사펩티드의 형태 및 5,5-디페닐하이덴토인에 의한 양이온 전달방해에 관한 이론적 연구)

  • Kiyull Yang;In Sun Koo;Ikchoon Lee;Chang-Kook Sohn
    • Journal of the Korean Chemical Society
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    • v.36 no.4
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    • pp.523-535
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    • 1992
  • The conformations of hexapeptides, their complexation with alkali cations and the inhibition of the cation transport by 5,5-diphenylhydantoin(DPH) were studied theoretically using ECEPP/2 and MM2 force field. Several low energy conformations of uncomplexed cyclic hexapepides are obtained, and they adopt compact conformations in which most amide hydrogens form intramolecular hydrogen bond to amide carbonyl oxygens. The complexation energy of the peptide with $Na^+$ ion and DPH is -60 kcaal/mol and -18 kcal/mol, respectively. However, no suitable cavity to bind metal cation exists for the local minima of the peptide, and the internal energy of the uncomplexed hexapeptide having cavity is higher than that of the uncomplexed global minimum of this work by 10 kcal/mol. Also, one of the most important amino acid residue to bind DPH is Glycine, and this can explain experimental observation that the replacement of Gly by Sarcosine (N-methyl Glycine) reduce the inhibition ability of the cation transport.

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