• 제목/요약/키워드: Jong-Hwa AN

검색결과 1,244건 처리시간 0.031초

A study on rotational motion control for ship steering motion control

  • Park, Seong-Hwan;Kim, Jong-Hwa
    • Journal of Advanced Marine Engineering and Technology
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    • 제40권2호
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    • pp.120-130
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    • 2016
  • In general, a series of ship steering motions is composed of a combination of translational motions and rotational motions of the ship. In particular, a series of rotational motions frequently occurs in narrow areas such as ports and canal zones. In this paper, a method was suggested for composing an integrated control algorithm based on the jog dial as a command instrument for rotational motion control. In order to realize the rotational motions, several algorithms were suggested for generating rotational commands, for selecting motion variables, for choosing reference input values for the motion variables, for computing required accelerations and thrusts, and for allocating thrusts to actuators. A simulation program was compiled to execute simulations for three rotational motions. Finally, the effectiveness of the suggested method was verified by analyzing the simulation results.

빅데이터 분석을 위한 비용효과적 오픈 소스 시스템 설계 (Designing Cost Effective Open Source System for Bigdata Analysis)

  • 이종화;이현규
    • 지식경영연구
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    • 제19권1호
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    • pp.119-132
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    • 2018
  • Many advanced products and services are emerging in the market thanks to data-based technologies such as Internet (IoT), Big Data, and AI. The construction of a system for data processing under the IoT network environment is not simple in configuration, and has a lot of restrictions due to a high cost for constructing a high performance server environment. Therefore, in this paper, we will design a development environment for large data analysis computing platform using open source with low cost and practicality. Therefore, this study intends to implement a big data processing system using Raspberry Pi, an ultra-small PC environment, and open source API. This big data processing system includes building a portable server system, building a web server for web mining, developing Python IDE classes for crawling, and developing R Libraries for NLP and visualization. Through this research, we will develop a web environment that can control real-time data collection and analysis of web media in a mobile environment and present it as a curriculum for non-IT specialists.

Separation and Purification of Useful Proteins Using Hydrogel Ultratiltration

  • Park, Chang-Ho;Son, Chang-Kyu;Park, Jong-Hwa;Chung, In-Sik
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제2권2호
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    • pp.113-116
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    • 1997
  • The hydrogel process is a different form of ultrafiltration and has been used to separate biological molecules. In this study, the gel pore size was predicted by pulse NMR technique and neural network using a database obtained from gel filtration chromatography and diffusion experiment. Recombinant alkaline phosphatase expressed in insect cells was concentratred 1.5 times by hydrogel ultrafiltration by swelling at 2$0^{\circ}C$ and collapsing at 35$^{\circ}C$ at 53-65% separation efficiency and 78-83% enzyme recovery. Wild and recombinant Autographa californica unclear polyhedrosis viruses (AcNPV) were also concentrated 1.4 and 1.6 times of the feed solution at 48.5 and 60.0% separation efficiency, respectively Hydrogel ultrafiltration appears to be an attractive alternative for the concentration of AcNPV and recombinant proteins from insect cells.

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Robust Diagnosis Algorithm for Identifying Broken Rotor Bar Faults in Induction Motors

  • Hwang, Don-Ha;Youn, Young-Woo;Sun, Jong-Ho;Kim, Yong-Hwa
    • Journal of Electrical Engineering and Technology
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    • 제9권1호
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    • pp.37-44
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    • 2014
  • This paper proposes a new diagnosis algorithm to detect broken rotor bars (BRBs) faults in induction motors. The proposed algorithm is composed of a frequency signal dimension order (FSDO) estimator and a fault decision module. The FSDO estimator finds a number of fault-related frequencies in the stator current signature. In the fault decision module, the fault diagnostic index from the FSDO estimator is used depending on the load conditions of the induction motors. Experimental results obtained in a 75 kW three-phase squirrel-cage induction motor show that the proposed diagnosis algorithm is capable of detecting BRB faults with an accuracy that is superior to a zoom multiple signal classification (ZMUSIC) and a zoom estimation of signal parameters via rotational invariance techniques (ZESPRIT).

자기등가회로법에 의한 유도전동기 과도상태해석 (An analysis of transient state for induction motor by using the magnetic equivalent circuit method)

  • 정종호;이은웅;조현길;김준호;이화수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.18-20
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    • 2002
  • In this paper, the construction elements of the induction motor was represented by the magnetic tube. The magnetic tube is basis of the magnetic equivalent circuit. The magnetic equivalent circuit method is convenient of complicated analysis of the transient state of the induction motor. Because the method is restriction on only one direction of magnetic flux. Air gap magnetomotive force was calculated by magnetic equivalent circuit method. Starting transient torque and phase current of the induction motor was confirmed by the theoretical calculation and the experiments.

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Modeling Circular Data with Uniformly Dispersed Noise

  • Yu, Hye-Kyung;Jun, Kyoung-Ho;Na, Jong-Hwa
    • 응용통계연구
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    • 제25권4호
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    • pp.651-659
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    • 2012
  • In this paper we developed a statistical model for circular data with noises. In this case, model fitting by single circular model has a lack-of-fit problem. To overcome this problem, we consider some mixture models that include circular uniform distribution and apply an EM algorithm to estimate the parameters. Both von Mises and Wrapped skew normal distributions are considered in this paper. Simulation studies are executed to assess the suggested EM algorithms. Finally, we applied the suggested method to fit 2008 EHFRS(Epidemic Hemorrhagic Fever with Renal Syndrome) data provided by the KCDC(Korea Centers for Disease Control and Prevention).

캣워크 구조물의 공기역학적 특성 (Aerodynamic Characteristics of Catwalk Structures)

  • 이승호;이한규;권순덕;김종화
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 춘계학술대회 논문집
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    • pp.105-110
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    • 2011
  • Catwalk structures are temporary walk ways for erection of main cables in suspension bridge. The aerodynamic characteristics of the catwalk structures are not well studied even though the catwalk structures are sensitive to wind action because of its flexibility. Present study demonstrates technical results obtained from wind tunnel tests of various catwalk structures. To obtain the aerostatic force coefficients of the floor system of catwalk, 1/14 and 1/4 scaled partial rigid models were fabricated and tested at the wind tunnel. In order to investigate the Reynolds number effects, the aerostatic force coefficients were measured at various wind velocities ranged from 5m/s to 30m/s. The test results revealed that the Reynolds number effects on aerostatic coefficients were not significant for the catwalk floor systems. An empirical equation for aerostatic force coefficients of catwalk are proposed based on the measured results.

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동안신경마비(動眼神經麻痺)에 대(對)한 한방치험(韓方治驗) 일례(一例) (A Case of the Oculomotor Nerve Palsy)

  • 김종한;최정화;박수연
    • 동의신경정신과학회지
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    • 제12궈1호
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    • pp.201-207
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    • 2001
  • Oculomotor nerve is the third cranial nerve, controlls four of the six extraocular muscles(superior rectus muscle, medial rectus muscle, inferior rectus muscle and inferior oblique muscle), levator palpebrae superioris muscle, cilliary muscle and muscle sphincter pupillae. In the oculomotor nerve palsy, limited oculogyration, diplopia, blepharoptosis, accomodation paralysis and mydriasis can be occured. We experienced an improved case of the oculomotor nerve palsy patient treated with oriental medicine for 25days. We used herbal medicine and acupuncture. Based on this experience, it is considered that oriental medicine can be applied to the treatment of the oculomotor nerve palsy.

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Effective BPM Implementation Strategies for Korea Firms

  • Hwa, Na-Jong;Phil, Jeong-Seon;Jang, In-Sook
    • 한국산업정보학회:학술대회논문집
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    • 한국산업정보학회 2007년도 춘계학술대회
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    • pp.103-109
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    • 2007
  • For Rapid change of business process, BPM(Business Process Management) has been required in order to help cooperations have a fast, active and easy to re-set business process. In the beginning of BPM introduction, there was a hash competition between Korean and foreign BPM solution companies but so far few studies have been accomplished. This study compared characters, related technologies and market situations of BPM Also, this study compared several Korean companies' case of BPM and researched critical success factors of BPM implementation. Thus this study presents an understanding for a proper way to adopt BPM to companies.

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Landsat TM 데이터에 의한 식생피복율과 지표면온도와의 관계 해석 (Analysis of Relationship between Vegetation Cover Rates and Surface Temperature Using Landsat TM Data)

  • 박종화;나상일;김진수
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.569-573
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    • 2005
  • Land surface temperature(LST) is one of the key parameters in physics and meteorology of land-surface processes on regional and global scales. Urban Heat Island(UHI), a meteorological phenomenon by which the air temperature in an urban area increases beyond that in the suburbs, grows with the progress of urbanization. Satellite remote sensing has been expected to be effective for obtaining thermal information of the earth's surface with a high resolution. The main purpose of this study is to produce LST map of Cheongju and to analyze the spatial distributions of surface heat fluxes in urban areas. This study, taking Cheongju as the study area, aims to examine relationship between vegetation cover rates and surface temperature, and to clarify a method for calculation surface temperature with Landsat TM thermal images.

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