• International Journal of Computer Science & Network Security
• /
• 제22권2호
• /
• pp.406-412
• /
• 2022

Storing large amounts of data has always been a big problem from the beginning of computing history. Big Data has made huge advancements in improving business processes by finding the customers' needs using prediction models based on web and social media search. The main purpose of big data stream processing frameworks is to allow programmers to directly query the continuous stream without dealing with the lower-level mechanisms. In other words, programmers write the code to process streams using these runtime libraries (also called Stream Processing Engines). This is achieved by taking large volumes of data and analyzing them using Big Data frameworks. Streaming platforms are an emerging technology that deals with continuous streams of data. There are several streaming platforms of Big Data freely available on the Internet. However, selecting the most appropriate one is not easy for programmers. In this paper, we present a detailed description of two of the state-of-the-art and most popular streaming frameworks: Apache Ignite and Hazelcast. In addition, the performance of these frameworks is compared using selected attributes. Different types of databases are used in common to store the data. To process the data in real-time continuously, data streaming technologies are developed. With the development of today's large-scale distributed applications handling tons of data, these databases are not viable. Consequently, Big Data is introduced to store, process, and analyze data at a fast speed and also to deal with big users and data growth day by day.

• 한국화재소방학회:학술대회논문집
• /
• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
• /
• pp.298-302
• /
• 2008

본 연구에서는 강원도 영동지역 주요 7가지 수종의 낙엽과 생엽을 대상으로 착화특성을 고찰하고자 강우 전과 후의 연료를 채취하여 연료의 함수율과 가연성과의 관계, KRS-RG-9000을 사용하여 착화특성을 고찰하였다. 시험결과 침엽수 낙엽은 강우 후 대기노출로부터 상온에서 144시간 경과 시 함수율이 10% 이하로 건조되어 가연성 물질이 발생할 수 있을 정도로 건조됨을 알 수 있었으며 활엽수는 자연발화온도가 높게 나타남에 따라 저온에서 착화지연시간이 길게 나타나 침엽수보다 내화력이 강함을 알 수 있었다.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
• /
• pp.111-114
• /
• 2012

The ignition behavior of single coal particles of five kindes of coal with different ranks (low volatile bituminous, low volatile sub-bituminous, high volatile bituminous, lignite) with particle size of $150-200{\mu}m$ was investigated at high heating rate condition. Particles were injected into a laminar flow reactor and the ignition behavior was observed with high speed cinematography. Sub-bituminous were observed to ignite homogeneously; however, low volatile bituminous coal and lignite undergo fragmentation prior to igntion. The observation was analyzed with previous work.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.643-646
• /
• 2005

We present new ramp-reset waveforms that realize fast addressing in AC-PDPs. These waveforms distort the distribution of wall charges on the surface of a phosphor layer: hence, the enhanced electric field helps to ignite a cell faster. They also reduce the black luminance: the divide of erasing ramp down discharges into two parts, i.e. a surface discharge and a vertical discharge, makes lower luminance.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2002년도 동계연구발표회 논문개요집
• /
• pp.152-153
• /
• 2002

The report on large tunneling magnetoresistance (TMR) at room temperature in magnetic tunnel junctions (MTJ), composed of two ferromagnetic electrodes separated by a thin insulating barrier, has ignite the intensive research both from scientific and technological points of view. A simple model proposed by Juliere has explained the observed TMR surprisingly well, where the TMR is expressed in terms of the spin polarization P of the ferromagnetic electrodes. (omitted)

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
• /
• pp.49-51
• /
• 2015

In this research, engine performance and emission variation according to equivalence ratio and ignition time is calculated by validated analysis model. LNG engine ignite by spark plug and spark ignition modeled using DPIK model and G-equation that modeled initial flame surface called kernel and velocity and position of flame front. Engine pressure and emission was validated with experimental data.

• 한국안전학회지
• /
• 제24권4호
• /
• pp.28-33
• /
• 2009

This study examined the mounting status of cigar lighter receptacles for vehicles and analyzed the tracking phenomenon that occurs when foreign material entered a cigar lighter receptacle to obtain data for the analysis of accident investigation. Regardless of the vehicle's output, cigar lighter receptacles are mounted in a vehicle horizontally, vertically, or at tilting or inclined angle. The tilting type cigar lighter receptacle is much easier to use but current leakage resulting from foreign materials (coffee, beverages, water, etc.) falling into the cigar lighter receptacle may cause a fire to start. This study used a vehicle battery (DC 12V) as a power supply for the tracking test and configured its circuit in the same way as that of an electrical device in a vehicle. The tracking phenomenon that occurred in the standby mode of the vehicle exhibited a fine flame and an irregular occurrence of smoke. While this tracking phenomenon was occurring, the leakage current and the reaching distance of the flame were measured to be approximately 930mA and $20{\sim}50cm$, respectively. It is thought that the resultant flame may ignite toluene, dust, cigarettes, etc. It was observed that as the tracking progressed, the internal metal socket melted and a hole was created, the surface of which was also severely carbonized. In addition, the electrical resistance of the carbonized conductive path was measured to be approximately $30{\Omega}$. It is thought that this much resistance may cause local heating when leakage current flows and could ignite any nearby flammable material.

• 한국안전학회지
• /
• 제39권2호
• /
• pp.1-8
• /
• 2024

Unwanted effects of electrostatic phenomena occur in various industries. Electrostatic problems originating from the human body in flammable atmospheres in the industry are especially concerning. A substantial volume of experimental data on the electrostatic charging voltages created on the human body owing to the rubbing of apparel were generated and reviewed during this study. The data were reviewed to determine whether the resultant charging levels of the human body are hazardous in flammable atmospheres. This study was conducted under several conditions, such as different fiber types used in apparel, shoe types, and relative humidities (RHs). The following conclusions were drawn in this study. ① The electrostatic charging levels of the human body owing to the rubbing of apparel increase with the increase in the surface resistances of apparel; however, the electrostatic charging levels may be different depending on the condition of the cloth surface. ② The discharging energy of 1.98-18.5 [mJ] from the human body exceeds the minimum ignition energy of most flammable materials, when removing an overcoat made of polyester, cotton and wool under severe conditions such as wearing height-raising shoes for men. ③ When removing antistatic apparel, the maximum discharging energy of 0.128 mJ from the human body is dangerous if the minimum ignition energy of the flammable material is between 10^-5-10^-4 [J] Grade; however, a minimum ignition energy of 10^-3 J Grade of the flammable material is considered safe. ④ While wearing antistatic shoes, the electrostatic charging voltage generated in the human body when removing an overcoat is 30 V; therefore, wearing such shoes is a suitable countermeasure when handling flammable materials. However, the antistatic abilities of shoes reduce when thick socks are worn. ⑤ As RH increases, the electrostatic charging levels of the human body decrease. ⑥ The electrostatic charging levels of the human body from removing a cotton overcoat can ignite the majority of flammable materials when RH is less than 30% under severe conditions such as wearing height-raising shoes for men.

• 한국화재소방학회논문지
• /
• 제22권3호
• /
• pp.246-251
• /
• 2008

일반적으로 유류화재의 경우 상온 상압 하에서 그 물리적 성질과 에너지 특성이 유사한 양상을 나타내나 식용유에 의한 화재발생은 그 특성이 매우 특이하여 취급자의 무지로 인한 화재가 자주 발생하고 있다. 따라서 본 연구에서는 식용유에 대한 에너지 특성과 그 물적 성질을 고찰한 연후 실제 연소실험을 통하여 식용유에 대한 물리적 성질을 검증하였다. 뿐만 아니라 실제 화재사례를 통하여 식용유에 의한 화재원인을 감식하였고 식용유화재 방지를 위한 대응방안을 고찰하여 제시 하였다.

• 한국화재소방학회논문지
• /
• 제15권4호
• /
• pp.34-40
• /
• 2001

HPMC의 자연발화는 일정한 주위온도에서 자연발화의 연구와 Godbret-Greenwald가 고안한 전기로에서 운상상태의 최소발화온도를 구하였으며, 시료를 용기에 충전했을 경우 용기의 크기가 클수록 발화한계 온도는 낮아졌으며 겉보기활성화에너지는 Frank-Kamenetskii의 열발화이론으로부터 계산하였고, 운상상태의 발화온도는 21%의 산소농도하에서 최소발화온도를 구하였으며, 산소농도 변화의 실험결과 산소농도 10%에서 발화되지 않았으며 한계산소농도를 구할 수 있었다.