• 문화기술의 융합
• /
• 제6권2호
• /
• pp.529-534
• /
• 2020

인류 문명의 발전은 산업화에 따른 도시의 발전과 운송 기술의 진화와 맥을 같이한다. 지금까지의 도시 발전은 수송비 절감과 한정된 중심업무 지구로서의 토지 이용 요구에 따라 진행되어왔다. 도시 인구 밀집도의 지속적인 증가는 지가상승, 교통 혼잡, 빈부격차, 공해발생 등과 같이 사회·경제적으로 많은 문제를 일으켜 왔고 현재의 도시 생태 시스템으로는 전반적인 해결에 어려움이 있다. 그러나 문제의 해결을 위한 실마리는 바로 도시생태계 내에서 찾을 수 있다. 서울 심야버스 운행 노선의 설계는 바로 심야의 도시 내 이동 인구의 흐름을 정보통신 기술을 이용해 분석하여 얻은 결과이다. 이렇듯 도시 문제의 해결은 도시 생태계의 분석에서 출발하는 것이 타당하다. 문제의 원인을 알았다면 시민의 삶의 질을 높이기 위해 빅데이터 플랫폼 구축이 필요하고 이를 통한 해결이 가능하다. 이 플랫폼의 중심에는 정보통신 기술의 기반 하에 도시의 구성 요소와 연결되어 실시간 수집, 분석 및 적용되는 빅데이터가 자리 잡고 있어야한다. 본 연구를 통해 지속 가능한 스마트 시티를 위한 빅데이터 플랫폼 구축과 적용 방안에 대하여 고찰한다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2014년도 전력전자학술대회 논문집
• /
• pp.215-216
• /
• 2014

This paper proposes a control algorithm for permanent magnet synchronous generator with a back-to-back three-level neutral-point clamped voltage source converter in a medium-voltage offshore wind power system under unbalanced grid conditions. The proposed control algorithm particularly compensates for the unbalanced grid voltage at the point of common coupling in a collector bus of offshore wind power system. This control algorithm has been formulated based on the symmetrical components in positive and negative rotating synchronous reference frames under generalized unbalanced operating conditions. Instantaneous active and reactive power are described in terms of symmetrical components of measured grid input voltages and currents. Negative sequential component of ac input current is injected to the point of common coupling in the proposed control strategy. The amplitude of negative sequential component is calculated to minimize the negative sequential component of grid voltage under the limitation of current capability in a voltage source converter. The proposed control algorithm makes it possible to provide a balanced voltage at the point of common coupling resulting in the generated power of high quality from offshore wind power system under unbalanced network conditions.

• International Journal of Computer Science & Network Security
• /
• 제21권6호
• /
• pp.11-16
• /
• 2021

At the present time, the number of accidents has enlarged speedily and in country like India per day there are about 204 accidents occurred. Accidents of two-wheeler compose a foremost segment of every accident and it can be true for the reason that two-wheelers like bikes not able to produce as many as security measurements normally incorporated in cars, truks and bus etc. General main rootcost of the two-wheeler accidents happen only when people community not remember to wearing a device helmet and during the driving time feels like sleep condition, alcohol disbursement, many of the drivers doesn't know heavy vehicles like Loory and buses approaching into very closer to their two wheelers, contravention of two wheelers in traffic rules and regulations. Let's overcome the above situations; our important objective is to develop an intelligent system device that can successfully facilitate in avoidance of every kind of problems. Suppose any of the above stated situations occurs, at that moment how system device identify and represents the commanders and community, and finally the stated situation be able to taken care of straight away without any further delay. A smart intelligent helmet system is a defending head covering used by rider for making bike riding safer than earlier. This is finished by incorporating sophisticated features like detecting the usage of helmet by the rider, connected Bluetooth module in helmet. In order to maintain the temperature inside the helmet device we need to include CPU fan module inside the device. RF based helmet prevents road accidents and identify whether people community is not using a component helmet or used. Main responsibility of the system is to detect accidents by vibration sensors, accelerometers and also with the help of modules global positioning system and global system for mobile commnicaiton module. A wireless communication device used to discover the accident area site location and likewise notifying the two-wheeler drived people's relatives and short message text information passed to the positioned hospitals.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제15권6호
• /
• pp.2168-2187
• /
• 2021

The smart grid replaces the traditional power structure with information inventiveness that contributes to a new physical structure. In such a field, malicious information injection can potentially lead to extreme results. Incorrect, FDI attacks will never be identified by typical residual techniques for false data identification. Most of the work on the detection of FDI attacks is based on the linearized power system model DC and does not detect attacks from the AC model. Also, the overwhelming majority of current FDIA recognition approaches focus on FDIA, whilst significant injection location data cannot be achieved. Building on the continuous developments in deep learning, we propose a Deep Learning based Locational Detection technique to continuously recognize the specific areas of FDIA. In the development area solver gap happiness is a False Data Detector (FDD) that incorporates a Convolutional Neural Network (CNN). The FDD is established enough to catch the fake information. As a multi-label classifier, the following CNN is utilized to evaluate the irregularity and cooccurrence dependency of power flow calculations due to the possible attacks. There are no earlier statistical assumptions in the architecture proposed, as they are "model-free." It is also "cost-accommodating" since it does not alter the current FDD framework and it is only several microseconds on a household computer during the identification procedure. We have shown that ANN-MLP, SVM-RBF, and CNN can conduct locational detection under different noise and attack circumstances through broad experience in IEEE 14, 30, 57, and 118 bus systems. Moreover, the multi-name classification method used successfully improves the precision of the present identification.

• 한국ITS학회 논문지
• /
• 제22권1호
• /
• pp.52-64
• /
• 2023

차내 혼잡은 대중교통 이용자들의 통행의 질과 관련된 주제라고 할 수 있다. 차량의 제한된 용량과 배차간격 등의 이유로 주로 이용수요가 많은 교통수단 및 운영노선에서 차내 혼잡이 발생되며 이는 실제로 이용자들이 경험하는 통행시간의 가치에 차이를 유발시킨다. 본 연구에서는 오후 첨두시 분석노선 광역버스를 이용하는 개별 통행자의 스마트카드 자료 정보를 기반으로 차내 혼잡에 따른 개별 통행자의 시간가치를 추정하였다. 특히, 차내 혼잡이 개별 통행자가 느끼는 시간가치에 미치는 영향의 크기와 그 형태에 대해서 정교하게 분석하기 위해 Box-Cox transformation로 변환한 변수를 포함하여 모형을 구축하였다. 추정 결과에서 도출된 혼잡승수를 이용하여 2층 버스 도입 시 차내 혼잡 감소에 따른 편익을 산정하였으며 이를 통해 본 연구에서 제시하고 있는 추정 결과의 유의미성과 적용방안에 대해 논의하였다.

• 전기전자학회논문지
• /
• 제27권4호
• /
• pp.657-667
• /
• 2023

배전계통에 연계되는 분산전원의 수가 증가함에 따라 계통 내 과전압 문제를 일으키지 않고 접속될 수 있는 한계접속용량인 photovoltaic(PV) hosting capacity(HC)를 추정하는 것이 매우 중요해졌다. 이에 본 연구에서는 접속점의 전압을 유지하는 제어를 수행하면서 향상된 hosting capacity를 추정하기 위한 방안을 제안하고 있다. 제안된 방안은 two-stage optimization framework로 구성되며 Stage 1에서 IEEE Std 1547-2018 가이드라인을 이용한 Volt-Var(VV) 및 Volt-Watt(VW) 제어 PV hosting capacity 추정을 수행한다. Stage 2에서는 VV 및 VW의 파라미터를 개선하는 절차를 거쳐 향상된 PV HC 값을 다시 도출해낸다. 제안한 방식의 성능 검증을 위해 IEEE 37-버스 시스템이 OpenDSS를 사용해 테스트되었으며 결과에서 제안된 방식의 적용을 통해 PV hosting capacity가 증가함을 확인하였다.

• International journal of advanced smart convergence
• /
• 제4권1호
• /
• pp.64-70
• /
• 2015

This paper proposes fluorescent electronic ballast with high power factor and low line input current harmonics. The system performance can be improved by a charged pump circuit. Details of design and circuit operation are described. The proposed electronic ballast is modified from single-stage half bridge class D electronic ballast by adding capacitor parallel with each power switch and setting the circuit parameter to operate under class DE inverter condition. By using this proposed method the DC bus voltage can be reduced around by 50% compare with conventional class D inverter circuit. Because the power switches are operated at zero voltage switching condition and low dv/dt of class DE switching. The experimental results show that the proper frequency of the prototype is around 50 kHz with input power factor of 0.982, $THD_i$ 10.2% at full load and efficiency of more than 90%.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2013년도 추계학술대회 논문집
• /
• pp.117-118
• /
• 2013

Recent global warming to the promotion of electric vehicles (EV), plug-in hybrid (PEV), including the next generation of cars and solar power, wind power and other renewable energy, and next-generation power grid (smart grid) are getting attention. In addition, the system utilizes the battery life in the industry and the convenience of a variety of social systems, economics, environmental impact, and the inherent potential to change significantly, and you can not walk into a next-generation industrial strategy and the need increases more and more present, and its early commercialization In order to do this, as well as a key energy source, the battery charger for charging efficiency technologies is essential. In this paper, fast charge multiple battery modules and optional modules that can charge distribution charge will be introduced.

• Journal of Multimedia Information System
• /
• 제3권4호
• /
• pp.161-168
• /
• 2016

In this paper, a power flow simulator, which visualizes power flow and system configuration, is proposed and implemented. Generally, it is necessary to prepare a text file with power-system descriptions, which is one of the barriers for power-flow simulations. The proposed simulator has a function of automatic generations of IEEE common data format files from user-drawn power-system diagrams. Therefore, it is possible for users to carry out simulations only by drawing power system on display. In addition, the proposed simulator also has a function that power-system diagram is illustrated automatically from an IEEE common data format file. By using this function, it is possible to visualize amounts and directions of power flows on the bus-system diagram, which helps users to comprehend network dynamics intuitively. Because the proposed simulator allows including renewable-resource generators in power systems, it is useful to evaluate the power distribution system. It is shown in this paper that the proposed simulator can make IEEE common data format files correctly and illustrate intuitive power flow.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2010년도 추계학술대회
• /
• pp.609-612
• /
• 2010

스마트폰(smartphone)은 휴대전화에 인터넷 통신과 정보검색 등 컴퓨터 지원 기능을 추가한 지능형 단말기로서 사용자가 원하는 어플리케이션(application)을 설치할 수 있는 것이 특징으로, 현 시대에 있어 하나의 문화가 되었을 정도로 크나큰 이슈가 되고 있고, 어플리케이션 개발 시장도 활발해졌으며, 크게 성장하고 있다는 점이다. 대중교통정보 어플리케이션의 사용 빈도가 높은 편이긴 하나, 유동인구 빈도수가 높은 수도권과 광역시 지역 중심으로 제공되는 있는 실정이다. 본 논문에서는 GPS(Global Positioning System) 기능이 활성화 되지 않은 지방지역 실정을 고려하여 안드로이드 플랫폼(android platform)을 이용한 스마트폰 기반 스쿨버스 어플리케이션 설계와 구현을 제안하려 한다.