• Title/Summary/Keyword: K5 system

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Intelligent Steering Control System Based on Voice Instructions

  • Seo, Ki-Yeol;Oh, Se-Woong;Suh, Sang-Hyun;Park, Gyei-Kark
    • International Journal of Control, Automation, and Systems
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    • v.5 no.5
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    • pp.539-546
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    • 2007
  • The important field of research in ship operation is related to the high efficiency of transportation, the convenience of maneuvering ships and the safety of navigation. For these purposes, many intelligent technologies for ship automation have been required and studied. In this paper, we propose an intelligent voice instruction-based learning (VIBL) method and discuss the building of a ship's steering control system based on this method. The VIBL system concretely consists of two functions: a text conversion function where an instructor's inputted voice is recognized and converted to text, and a linguistic instruction based learning function where the text instruction is understood through a searching process of given meaning elements. As a study method, the fuzzy theory is adopted to build maneuvering models of steersmen and then the existing LIBL is improved and combined with the voice recognition technology to propose the VIBL. The ship steering control system combined with VIBL is tested in a ship maneuvering simulator and its validity is shown.

The Performance Improvement of Excitation System using Robust Control with DATABASE

  • Hong, Hyun-Mun;Jeon, Byeong-Seok;Kim, Jong-Gun;Lee, Sang-Hyuk
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.1
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    • pp.83-87
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    • 2005
  • This paper deals with the design and evaluation of the robust controller for a synchronous generator excitation system to improve the steady state and transient stability. The nonlinear characteristics of the system is treated as model uncertainties, and then the robust control techniques are introduced into the power system stability design to take into account these uncertainties at the controller design stage. The performance of the designed controller is examined by extensive non-linear time domain simulation. It is shown that the performance of the robust controller is superior to that of the conventional PI controller. This paper also proposes an improved digital exciter control system for a synchronized generator using a digitally designed controller with database. Results show that the proposed control system manifests excellent control performance compared to existing control systems. It has also been confirmed that it is easy for the proposed control system to implement digital control.

Performance Comparison of Hot-gas Bypass Types with the Variation of Refrigeration Load (부하변화에 따른 hot-gas 바이패스 방식별 성능 비교)

  • Baek, Seung-Moon;Yoon, Jung-In;Son, Chang-Hyo;Heo, Jung-Ho
    • Journal of Power System Engineering
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    • v.18 no.5
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    • pp.48-54
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    • 2014
  • In this paper, three refrigeration systems bypassing hot-gas to compressor outlet, compressor and condenser outlet and evaporator inlet are theoretically compared to offer basic design data for performance depending on cooling load using a HYSYS program. The main results are summarized as follows : First, the COP of third system is the highest. Next, the COP of second system is higher than first one. And, the temperature of compressor inlet of third system is constant for all cooling load. Compared to first and second system, the compressor inlet temperature of the first system is higher than second one for all cooling loads. From the above results, third system, which is bypassing hot-gas to evaporator inlet, is more advantageous when considering the precise temperature control and excellent performance of oil and water cooler of industrial machine.

Evaluation of Dynamic Behavior for Pile-Supported Slab Track System by 3D Numerical Analysis (3차원 수치해석을 통한 궤도지지말뚝의 동적거동 평가)

  • Yoo, Mintaek;Back, Mincheol;Lee, Ilhwa;Lee, Jinsun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.21 no.5
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    • pp.255-264
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    • 2017
  • Dynamic numerical simulation of pile-supported slab track system embedded in a soft soil and embankment was performed. 3D model was formulated in a time domain to consider the non-linearity of soil by utilizing FLAC 3D, which is a finite difference method program. Soil non-linearity was simulated by adopting the hysteric damping model and liner elements, which could consider soil-pile interface. The long period seismic loads, Hachinohe type strong motions, were applied for estimating seismic respose of the system, Parametric study was carried out by changing subsoil layer profile, embankment height and seismic loading conditions. The most of horizontal permanent displacement was initiated by slope failure. Increase of the embedded height and thickness of the soft soil layer leads increase of member forces of PHC piles; bending moment, and axial force. Finally, basic guidelines for designing pile-supported slab track system under seismic loading are recommended based on the analysis results.

Effect of Cholecystokinin on Serotonin Release from Cultured Neurons of Fetal Rat Medulla Oblongata (연수 신경세포 배양에서 세로토닌 분비에 대한 Cholecystokinin의 작용)

  • Song Dong-Keun;Cho Hyun-Mi;Lee Tae-Hee;Suh Hong-Won;Kim Yung-Hi
    • The Korean Journal of Pharmacology
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    • v.31 no.1 s.57
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    • pp.11-15
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    • 1995
  • Serotonergic neurons in medulla oblongata play an important role in the endogenous descending pain inhibitory system. To illucidate the factors involved in the regulation of medullary serotonergic neurons, we studied the effects of cholecystokinin (CCK) and agents acting on various second messenger systems on 5-hydroxytryptamine (5-HT) release from cultured neurons of rat fetal (gestational age 14th day) medulla oblongata. Cultured cells maintained for 10 days in vitro were stimulated for 48 hours with CCK or other neuropeptides at 10 micromolar concentration. CCK ($10{\mu}M$) and substance P ($10{\mu}M$) significantly increased. 5-HT release. However, somatostatin, proctolin, thyrotropin releasing hormone, and interleukin-6 did not have any effects on 5-HT release. Nimodipine ($1{\mu}M$), a calcium channel blocker, almost completely, and calmidazolium ($1{\mu}M$), a calmodulin antagonist, significantly inhibited the CCK-induced 5-HT release. The total 5-HT content (intracellular 5-HT plus released 5-HT) was significantly increased by CCK. However, the intracellular 5-HT content was not significantly changed by CCK. Forskolin ($5{\mu}M$), an adenylate cyclase activiator, but not $2{\mu}M$ phorbol myristate acetate (PMA), a protein kinase C activator, significantly enhanced 5-HT release. The total 5-HT content (intracellular 5-HT plus released 5-HT) was significantly increased by forskolin. However, the intracellular 5-HT content was not significantly changed by forskolin. PMA had no effect on intracellular 5-HT levels. These results suggest that CCK regulates serotonergic neurons in the medulla oblongata by enhancing 5-HT secretion through calcium influx and caimodulin, and that cyclic AMP system but not protein kinase C system is involved in 5-HT release.

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Development of Vessel Communication System for Integrated Management and Inter-exchange of Maritime Data (해상 데이터 통합 관리 및 상호교환을 위한 선박 통신 시스템 개발)

  • Kang, Nam-seon;Kim, Ji-goo;Lee, Seon-ho
    • Journal of Advanced Navigation Technology
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    • v.19 no.5
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    • pp.354-362
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    • 2015
  • In this study, for integrated management and inter-exchange of operational data generated by ships and land-side information on safe and business, a vessel communication system with modular functions was designed that applied high efficiency compression, least-cost algorithms and Inmarsat FBB connection automation system. Performance test at the KTsat Kumsan satellite earth station; system was found to delivered an average transfer speed of 7 kB/S, which was significant improvement from the existing commercial product's average speed of 5 kB/S. It also delivered twice the efficiency of the existing product in terms of compression rate and transfer of the most widely used office files in maritime businesses.

A Study on Treatment of Soils Contaminated by Diesel and Kerosene Using Hydrogen Peroxide Catalyzed by Naturally Occurring Iron Minerals (디젤과 등유로 오염된 토양의 철광석으로 촉매화된 과수를 이용한 처리에 관한 연구)

  • Choi, Jin-Ho;Kim, Sang-Dae;Moon, Sei-Ki;Kong, Sung-Ho
    • Applied Chemistry for Engineering
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    • v.10 no.1
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    • pp.24-29
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    • 1999
  • Naturally-occurring iron minerals, goethite, magnetite, and hydrogen peroxide were used to catalyze and initiate Fenton-like oxidation of silica sand contaminated with mixture of diesel and kerosene in batch system. Optimal reaction conditions were investigated by varying pH(3, 7), $H_2O_2$ concentration(0%, 1%, 7%, 15%, 35%), initial contaminant concentration(0.2, 0.5, 1.0 g-mixture of diesel and kerosene/ kg-soil), and iron mineral contents(1, 5, and 10 wt % magnetite or goethite). Contaminant degradations in silica sand-iron mineral-$H_2O_2$ systems were identified by determining total petroleum hydrocarbon(TPH) concentration. The optimal pH of the system was 3. The system which iron minerals were the only iron source was more efficient than the system with $FeSO_4$ solution due to lower $H_2O_2$ consumption. In case of initial contaminant concentration of 1g-contaminant/kg-soil with 5 wt % magnetite, addition of 0%, 1%, 7%, 15%, and 35% of $H_2O_2$ showed 0%, 24.5%, 44%, 52%, and 70% of TPH reduction in 8 days, respectively. When the mineral contents were varied 0, 1, 5, and 10wt%, removal of contaminants were 0%, 33.5%, 50%, and 60% for magnetite and 0%, 29%, 41%, and 53% for goethite, respectively. Reaction of magnetite system showed higher degradation than that of goethite system due to dissolution of iron and mixed presence of iron(II) and iron(III); however, dissolved iron precipitated on the surface of iron mineral and seemed to cause reducing electron transfer activity on the surface and quenching $H_2O_2$. The system using goethite has better treatment efficiency due to less $H_2O_2$ consumption. When cach system was mixed by shaker, removal of contaminants increased by 41% for magnetite and 30% for goethite. Results of this study showed catalyzed $H_2O_2$ system made in-situ treatment of soil contaminated with petroleum possible without addition of iron source since natural soils generally contain iron minerals such as magnetite and goethite.

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Analysis of Train Operation Obstacle Using Number of Failures and Delay Time of Electric Door System (전기식 도어시스템의 고장건수 및 지연시간을 활용한 열차운행장애 분석)

  • Lee, Bon Hyung;Kim, Doo-Hyun;Kim, Sung-Chul
    • Journal of the Korean Society of Safety
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    • v.35 no.1
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    • pp.12-17
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    • 2020
  • This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

Fault Detection of Governor Systems Using Discrete Wavelet Transform Analysis

  • Kim, Sung-Shin;Bae, Hyeon;Lee, Jae-Hyun
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.5
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    • pp.662-673
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    • 2012
  • This study introduces a condition diagnosis technique for a turbine governor system. The governor system is an important control system to handle turbine speed in a nuclear power plant. The turbine governor system includes turbine valves and stop valves which have their own functions in the system. Because a turbine governor system is operated by high oil pressure, it is very difficult to maintain under stable operating conditions. Turbine valves supply oil pressure to the governor system for proper operation. Using the pressure variation of turbine and governor valves, operating conditions of the turbine governor control system are detected and identified. To achieve automatic detection of valve status, time-based and frequency-based analysis is employed. In this study, a new approach, wavelet decomposition, was used to extract specific features from the pressure signals of the governor and stop valves. The extracted features, which represent the operating conditions of the turbine governor system, include important information to control and diagnose the valves. After extracting the specific features, decision rules were used to classify the valve conditions. The rules were generated by a decision tree algorithm (a typical simple method for data-based rule generation). The results given by the wavelet-based analysis were compared to detection results using time- and frequency-based approaches. Compared with the several related studies, the wavelet transform-based analysis, the proposed in this study has the advantage of easier application without auxiliary features.

Investigation on the Management Status of Incentive Pay System in Hospital and Strategy to Invigorate (병원의 성과급제 운영실태 및 활성화 전략)

  • Moon, Young-Jeon;Park, Jae-San;Ahn, In-Whan
    • The Korean Journal of Health Service Management
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    • v.5 no.1
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    • pp.31-44
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    • 2011
  • The objectives of this study were first to inspect the background information of an incentive pay system in hospitals, which provide specialized services for the public, the current status of hospitals with the system, as well as effects produced by introducing it, and then to come up with measures to invigorate the system. According to the findings of a survey, a total of 123 out of 150 hospitals responded that they applied the system to their HR management, some fully or some partially, which accounts for 82.0 percent. This study suggested that the following strategies to invigorate the incentive pay system: having a clear objective when adopting the system; concerted performance targets; practical yet worth challenging business objectives; transparent information disclosure; and establishing a confidence-building system between labor and management. Mutual trust between labor and capital should be a key factor for the successful implementation of the incentive pay system.