• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2005년도 춘계학술발표회
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• pp.7-12
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• 2005

선박은 하나의 거대한 인간-기계시스템으로써 작업자와 시스템간의 상호 작용이 얼마나 잘 이루어지는가에 따라 수행하고자 하는 직무와 수행도에 영항을 미치게 된다. 선교 내에는 시각 표시 장치뿐만 아니라 청각 표시 장치로부터 나오는 많은 신호들이 존재한다. 그 중 장비의 알람(alarm)에 대한 인간의 인지능력에 대한 연구는 부족한 상태이다. 본 연구에서는 auditory icons과 sounds의 비교 평가를 통하여 알람에 대한 작업자의 인지에 대한 연구를 하였다. 실험결과 auditory icons를 사용한 경우 sounds 보다 더 빠르고 정확하게 인지 할 수 있는 것으로 나타났다 선교 내 청각적 표시장치의 성능 기준 그리고 현재 논의 되고 있는 통합 선교 알람 시스템을 위한 기초 자료로 본 연구의 결과가 이용될 수 있을 것이라 생각된다.

• 수산해양기술연구
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• 제49권3호
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• pp.301-310
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• 2013

To suggest a standard concerning with the arrangement of bridge equipment, the authors conducted the video observations with 3CCD (charge coupled device) cameras installed on the ceil of the bridge for monitoring the working activities of two bridge teams (the skipper/mate1 and the skipper/mate2) in a Korean coastal large trawler(gross tonnage: 139) for five days from July 30th. 2010 and analyzed of the data. Work elements coded by the work activities were input on the sheet of work analysis by the time unit of 1 sec according to the time occurred. A single work element among the work activities for every 5 minutes was denoted as the number of occurrence. The frequency of equipment usage was limited only in the usage of the equipment. In the case of the navigation and the towing net two ranks were integrated and analyzed. On the other hand, in the case of the casting net and the hauling net, two processes were integrated to as one and then analyzed separately as two ranks. As the results, 15 elements of work was carried out between two bridge teams for the observation; lookout, radar, GPS plotter, fish finder, net monitor, fishing deck, RPM indicator, rudder angle indicator, compass card, for maneuver; steering, ship speed control, trawl winch operation and external communications, paper works and others. It was found that the work load of the skipper per 5 minutes accordance with the navigation, the casting net, the towing net and the hauling net are 20.5 times, 11.9 times, 38.0 times and 9.5 times respectively, the mates are 65.2 times, 66.5 times, 85.7 times and 59.1 times respectively. The radar was shown the highest frequency of the equipment usage and the next was the fish finder, the GPS plotter and the external communications in the case of the navigation. In the case of the towing net the frequency of usage was high the ranking as the radar, the net monitor, the fish finder, the GPS plotter, the steering system and the external communications. In the case of the integrated process both of the casting and hauling net the trawl winch was shown the highest frequency to the skipper and the next was the GPS plotter and the radar, and the steering system was shown the highest frequency to the mate and the next was the radar, the ship speed control system, the GPS plotter, the net monitor and the fish finder.

• 해양환경안전학회지
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• 제11권2호
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• pp.33-40
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• 2005

기술의 발전에 따라 다양한 항해 계기들이 개발되고 있으나, 인간 과실에 의한 해양사고는 지속적으로 발생하고 있다. 따라서 사고를 감소시키기 위해 항해 장비들을 인간공학적으로 배치하고 설계하는 것이 관심의 대상이 되고 있다. 이러한 흐름에 각 국의 선급 및 해운 관련 기구에서는 인간공학적 개념을 적용한 통합선교시스템(Integrated Bridge System : IBS)에 대한 규정을 마련하고 있으며, IBS는 인간 과실로 인한 해양사고를 감소시키기 위한 설계와 정보의 제공을 중심으로 발전 할 것으로 예상된다. IBS의 일환으로, 선박 운항 시 항행정보를 하나의 모니터에 보여주는 Conning Display는 선교 근무자가 필요한 정보를 얻기 위해 취하는 부수적인 행동, 시간 등을 단축시킨다. 그러나 Conning Display 설계에 있어 표준화된 규범이 없으므로 객관적 연구가 필요한 실정이다. 본 논문에서는 설문조사와 스케치 기법, 휴리스틱 평가 등의 방법들을 통해 Conning Display의 인간공학적 설계를 위한 요소를 추출하였다. 이를 바탕으로 새로운 Conning Display를 제작하여 기존 fouling Display와 비교, 평가 실험을 실시하였다. 본 논문의 결과를 통해 향후 더 나은 Conning Display를 설계, 개발하는데 있어 인간공학적 지표를 제시하고 하나의 표본으로 사용될 수 있을 것이라 사료된다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.745-748
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• 2001

디지털 선박은 자율운항 제어 시스템(Intelligent Navigation System), 선박자동식별 시스템(Automatic Identification System), 위성통신망 원격제어 시스템(Integrated Maritime Information Technology)을 기반의 One-man Bridge 시스템을 갖는 차세대 선박을 나타낸다 INS 시스템에서는 선박의 항해와 관련된 기능을 수행하며, 최적항로 계획, 좌초 및 충돌방지 기법, 경제적 운항, 엔진통합제어, 내항성 성능평가 등의 기능이 디지털 GIS(Geographic Information System) 기반의 환경에서 제공된다. AIS 시스템은 선박과 선박간 또는 선박과 관제소간에 선박의 항해 관련 정보를 주기적으로 전송하여 충돌 방지를 기능을 제공하며, IMIT 시스템은 선박내의 통합 플랫폼을 제공하여 선내 네트워크 통합 솔루션을 제공한다. 또한, IMIT 시스템은 위성통신(INMARSAT, OrbComm, 해양관측위성)을 통해 선박과 관제소와의 데이터 송수신을 지원하여, 관제소에서 선박의 항해 상태를 감시하고 선박에 해양 환경정보, 조선소에서의 선박관련 정보 등을 제공하는 기능을 갖는다. 본 논문에서는 디지털 선박의 전체적인 시스템 구현방안과 세부 시스템별 구현방안에 대해 소개하며, 디지털-lT 기반의 차세대 선박에 대한 방향을 제시하도록 한다.

• Journal of Power Electronics
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• 제17권1호
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• pp.222-231
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• 2017

In this paper, a new architecture for a cost-effective power conditioning systems (PCS) using a single-sourced asymmetric cascaded H-bridge multilevel inverter (MLI) for photovoltaic (PV) applications is proposed. The asymmetric MLI topology has a reduced number of parts compared to the symmetrical type for the same number of voltage level. However, the modulation index threshold related to the drop in the number of levels of the inverter output is higher than that of the symmetrical MLI. This problem results in a modulation index limitation which is relatively higher than that of the symmetrical MLI. Hence, an extra voltage pre-regulator becomes a necessary component in the PCS under a wide operating bias variation. In addition to pre-stage voltage regulation for the constant MLI dc-links, another auxiliary pre-regulator should provide isolation and voltage balance among the multiple H-bridge cells in the asymmetrical MLI as well as the symmetrical ones. The proposed PCS uses a single-ended DC-DC converter topology with a coupled inductor and charge-pump circuit to satisfy all of the aforementioned requirements. Since the proposed integrated-type voltage pre-regulator circuit uses only a single MOSFET switch and a single magnetic component, the size and cost of the PCS is an optimal trade-off. In addition, the voltage balance between the separate H-bridge cells is automatically maintained by the number of turns in the coupled inductor transformer regardless of the duty cycle, which eliminates the need for an extra voltage regulator for the auxiliary H-bridge in MLIs. The voltage balance is also maintained under the discontinuous conduction mode (DCM). Thus, the PCS is also operational during light load conditions. The proposed architecture can apply the module-integrated converter (MIC) concept to perform distributed MPPT. The proposed architecture is analyzed and verified for a 7-level asymmetric MLI, using simulation results and a hardware implementation.

• 한국방재학회 논문집
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• 제2권4호
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• pp.97-116
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• 2002

In this papers, a finite element formulation is proposed for dynamic analysis of vehicle-bridge interaction problems under realistic loading conditions. Although the formulation presented in this paper is based on the consideration of only a single traversing vehicle, it can be extended to include several different bridge configurations. The traversing vehicle and the vibrating bridge superstructure are considered as an integrated system. Hence, although material and geometric nonlinearities are excluded, this introduces nonlinearity into the problem. Various vehicle models, including those with suspension systems, are considered. Traveling speed of the vehicle can be varied. The finite element discretization of the bridge structure permits the inclusion of arbitrary geometrical configurations, and surface and boundary conditions. To obtain accurate solutions, time integration of the equation of vehicle-bridge motion is carried out by using the Newmark method in connection with a predictor-corrector algorithm.

• Earthquakes and Structures
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• 제26권2호
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• pp.149-162
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• 2024

Aiming at the current research on the dynamic response analysis of the vehicle-bridge system under earthquake, which fails to comprehensively consider the impact of seismic wave incidence angles, terrain effects and soil-structure dynamic interaction on the bridge structure, this paper proposes a multi-point excitation input method that can consider the oblique incidence seismic P Waves based on the viscous-spring artificial boundary theory, and verifies the accuracy and feasibility of the input method. An overall numerical model of vehicle-bridge-soil foundation system in valley terrain during oblique incidence of seismic P-wave is established, and the effects of seismic wave incidence characteristics, terrain effects, soil-structure dynamic interactions, and vehicle speeds on the dynamic response of the bridge are analyzed. The research results indicate that with an increase in P wave incident angle, the vertical dynamic response of the bridge structure decreased while the horizontal dynamic response increased significantly. Traditional design methods which neglect multi-point excitation would lead to an unsafe structure. The dynamic response of the bridge structure significantly increases at the ridge while weakening at the valley. The dynamic response of bridge structures under earthquake action does not always increase with increasing train speed, but reaches a maximum value at a certain speed. Ignoring soil-structure dynamic interaction would reduce the vertical dynamic response of the bridge piers. The research results can provide a theoretical basis for the seismic design of vehicle-bridge systems in complex mountainous terrain under earthquake excitation.

• Journal of Power Electronics
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• 제16권2호
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• pp.512-521
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• 2016

Cascaded H-bridge multilevel (CHBML) inverters usually include a large number of isolated dc-voltage sources. Some faults in the dc-voltage sources result in unequal cell dc voltages. Unfortunately, the conventional phase-shifted carrier (PSC) PWM method that is widely used for CHBML inverters cannot eliminate low frequency sideband harmonics when the cell dc voltages are not equal. This paper analyzes the principle of sideband harmonic elimination, and proposes an improved PSCPWM that can eliminate low frequency sideband harmonics under the condition of unequal dc voltages. In order to calculate the carrier phases, it is necessary to solve transcendental equations for low frequency sideband harmonic elimination. Therefore, an approach based on the artificial bee colony (ABC) algorithm is presented in this paper. The proposed PSCPWM method enhances the reliability of CHBML inverters. The proposed PSCPWM is not limited to CHBML inverters. It can also be applied to other types of multilevel inverters. Simulation and experimental result obtained from a prototype CHBML inverter verify the theoretical analysis and the achievements made in this paper.

• Smart Structures and Systems
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• 제14권5호
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• pp.917-942
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• 2014

Multivariate statistics based damage detection algorithms employed in conjunction with novel sensing technologies are attracting more attention for long term Structural Health Monitoring of civil infrastructure. In this study, two practical data driven methods are investigated utilizing strain data captured from a 4-span bridge model by Fiber Bragg Grating (FBG) sensors as part of a bridge health monitoring study. The most common and critical bridge damage scenarios were simulated on the representative bridge model equipped with FBG sensors. A high speed FBG interrogator system is developed by the authors to collect the strain responses under moving vehicle loads using FBG sensors. Two data driven methods, Moving Principal Component Analysis (MPCA) and Moving Cross Correlation Analysis (MCCA), are coded and implemented to handle and process the large amount of data. The efficiency of the SHM system with FBG sensors, MPCA and MCCA methods for detecting and localizing damage is explored with several experiments. Based on the findings presented in this paper, the MPCA and MCCA coupled with FBG sensors can be deemed to deliver promising results to detect both local and global damage implemented on the bridge structure.

• 한국정보통신학회논문지
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• 제19권6호
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• pp.1301-1306
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• 2015

본 논문은 실생활에서 낭비되는 다양한 에너지 손실 중 주유소, 세탁소 등에서 손실되는 휘발성 유기화합물 (VoCs : Volatile organic Compounds)을 재활용하는 장치를 지능화하고 자동화 하는데 있다. 또한, 지그비(zigbee) 모듈 및 TCP/IP 통신기술을 활용한 ICT(Information Communication Technology) 기술을 도입하여 액화기를 원격지에서 모니터링하고 관리할 수 있는 통합관리시스템을 제시한다. 뿐만아니라, 안드로이드(android) 기반의 스마트 앱(App.)를 개발하여 원격지에서 관리할 수 있는 서비스 모델을 제시하고자 한다. 본 논문의 구성은 MCU 기반의 지능형 액화기 제어시스템의 구성과 지그비(zigbee) 기반의 브릿지(bridge) 모듈내부에 구현되는 통신 프로토콜을 제시한다. 통합관리시스템의 모바일 서비스를 위하여 안드로이드(android) 기반의 스마트 앱의 개발과 액화기 원격지 관리용 DB 서버(MS SQL 2012)와 웹서버(OS:Windows 2008)를 제시한다.