• Journal of the Korean Institute of Gas
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• v.11 no.1 s.34
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• pp.23-28
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• 2007

This paper presents an experimental investigation on the sealing defects and cracks of O-rings and a valve packing of a gas valve for a LPG cylinder. O-ring in which stops a gas leakage of a liquefied petroleum gas is very important for a LPG valve safety. Valve packing is to open and close a gas flow port for supplying and charging a LPG fuel. The sealing performance of two sealing units ism related to the leak safety and long lift of a gas valve. The investigated results show that most of O-rings was failed due to a circumferential crack in which is caused by partial press bonding failure near the partition zone and an excess compression rate. Some of the O-ring failure was originated by an extrusion of an excessive leak pressure of a LP gas. Thus, this paper strongly recommends a tight quality control and a safety guarantee system of O-rings and valve packing to guarantee a leak safety and to extend a service lift of a gas valve. At the end, a warranty policy of the sealing units should be adopted for increasing a product quality and safety of a gas valve.

• Journal of the Korean Institute of Gas
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• v.23 no.6
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• pp.1-7
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• 2019

Most oil refineries and chemical plants have flare systems designed to mitigate pressure rises in process facilities in case of emergencies that require the release of large amounts of gas due to sudden process shutdowns such as power outages. However, the rise of the flame of the flare system causes civil complaints from residents around the factory due to visible pollution, and economic loss occurs in the company, which requires constant management. In this study, two items were diagnosed and analyzed in order to derive the optimal operation method of flare system. First, to detect the cause of the rise in flame height, the acoustic leak detector was used to check gas leaks in safety valves and pressure control valves. Second, to identify the cause of flame instability, the pulsation phenomenon was diagnosed through the CFD simulation and modeling experiments of the sealing drum. By confirming the leak at 4.3% of the safety valve and 10% of the pressure control valve, the cause of abnormal sparking was derived. The information presented in this study can be easily applied to any company that has a flare system, and is expected to prevent complaints and product loss.

• Journal of the Korean Ceramic Society
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• v.40 no.1
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• pp.52-61
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• 2003

$SrBi_2Ta_2O_9(SBT)$and$ZrO_2$thin films for MFIS structure(Metal-Ferroelectric-Insulator-Semiconductor) were deposited by RF magnetron sputtering method. In order to investigate the effect of heat treatment of insulator layers and MFIS structure, the insulator layers were heat treated from $550^{circ}C;to; 850^{\circ}C$in conventional furnace or RTA furnace under$O_2$and Ar ambient, respectively. After then, C-V characteristics and leakage current were measured. The capacitor with 20 nm thick $ZrO_2$layer treated at RTA$750^{circ}C;in;O_2$ atmosphere had the largest memory window. The C-V and leakage current characteristics of the$Pt/SBT(260nm)/ZrO_2(20nm)/Si$structure were better than those of$Pt/SBT(260nm)/Si$ structure. These results showed that$ZrO_2$films took a role of buffer layer effectively.

• Fire Science and Engineering
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• v.34 no.3
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• pp.43-48
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• 2020

The purpose of this study is to develop an earth leakage alarm circuit breaker, equipped with a leakage alarming function (JER-E2S, ETECKOREA Co., Korea), and to analyze its characteristics. The developed mechanism is exclusively used for single-phase and 220 V circuits, with a rated current of 32 A, 20 A, 20 A (for restrooms), 16 A, etc. It satisfies all characteristics of existing earth leakage circuit breakers (ELB). If a fire current, which is a resistive leakage current (Igr), flows through an electric line, the device detects the leakage current in real time and warns against the leakage through a blinking LED lamp. Since the developed device displays a tolerance to a capacitative leakage current (Igc) that inevitably occurs in LED lamps, communication devices, etc., it ensures a stable power supply. In addition, the earth leakage alarm circuit breaker protects against power failure due to a momentary ground fault. Therefore, it can supply power without the risk of the circuit breaker malfunctioning due to a momentary ground fault caused by water droplets, leaves, etc. Moreover, with a standby power of less than 0.1 W, the developed earth leakage alarm circuit breaker exhibits a power saving performance that is 3~8 times greater than that of other ELBs. Installation of approximately 10 earth leakage alarm circuit breakers in one apartment household, with an area of 120 ㎡, can save 2~5 kWh per month. Therefore, the developed earth leakage alarm breaker not only satisfies the characteristics of existing earth leakage breakers, but also exhibits outstanding power supply quality since it has the functions of electric fire prevention and malfunction prevention. Therefore, this device can innovatively contribute to electric fire prevention.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.409-409
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• 2013

최근, 집적 소자의 미세화에 따라 늘어난 배선 신호 지연 및 상호 간섭, 그리고 소비 전력의 증가는 초고집적 소자 성능 개선에 한계를 가져온다. 이에 따라 기존의 알루미늄(Al)/실리콘 절연 산화막은 구리(Cu)/저유전율 박막(low-k)으로 대체되고 있고, 이는 소자 성능 개선에 큰 영향을 미친다. 그러나 Cu는 Si과 low-k 내부로 확산이 빠르게 일어나 소자의 비저항을 높이고, 누설 전류를 일으키는 등 소자의 성능을 저하시킬 수 있는 문제점을 가지고 있다. 이러한 Cu의 확산을 막기 위하여 Ta, TaN 등과 같은 확산방지막에 대한 연구가 활발히 진행되어 왔으나, 배선 공정의 집적화와 low-k 대체에 따른 공정 및 신뢰성 문제로 인해 새로운 확산방지막의 개발이 필요하게 되었다. 이를 위해, 본 연구에서는 Cu-V 합금을 사용하여 low-k 기판 위에 확산방지막을 자가 형성 시키는 공정에 대한 연구를 진행하였다. 다양한 low-k 기판에서 열처리조건에 따른 Cu-V 합금의 특성을 확인하기 위해 4-point probe를 통한 비저항 평가와 XRD (X-ray diffraction) 분석이 이뤄졌다. 또한, TEM (transmission electron microscope)을 이용하여 $300^{\circ}C$에서 1 시간 동안 열처리를 거쳐 자가형성된 V-based interlayer가 low-k와 Cu의 계면에서 균일하게 형성된 것을 확인하였다. 형성된 V-based interlayer의 barrier 특성을 평가하고자 Cu-V합금/low-k/Si 구조와 Cu/low-k/Si 구조의 leakage current를 비교 분석하였다. Cu/low-k/Si 구조는 비교적 낮은 온도에서 leakage current가 급격히 증가하는 양상을 보였으나, Cu-V 합금/low-k/Si 구조는 $550^{\circ}C$의 thermal stress 에서도 leakage current의 변화가 거의 없었다. 이러한 결과를 바탕으로 열처리를 통해 자가형성된 V-based interlayer의 Cu/low-k 간 확산방지막으로서 가능성을 검증하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.11-14
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• 2009

The implementation of gelled propellants systems offers high performance, thrust-control, energy management of propulsion, storability, and high density impulse of solid propulsion. Present study focused on the spray behavior of liquid sheets formed by impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are then compared with experiments conducted on spray images formed by impinging jets concerning with air-blast effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure, closed rim pattern shape appeared. As increasing air mass flow rate(decreasing GLR), spray breakup and atomization phenomenon better improved and spray structure instabilities for the effect of air-blast are also increased.

• Journal of Digital Convergence
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• v.12 no.7
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• pp.1-10
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• 2014

In February 2014 Korean Bar Association has amended Professional Ethics Code as to stipulate attorney's duty to protect personal information. While existing Korean law and Professional Ethics Code has made attorney to keep client's confidential information, attorney's newly promulgated obligation has its meaning in that personal information of subject other than client is not protected through confidentiality rules, given that confidentiality obligation is interpreted to protect only client's information relating to representation. Moreover, duty to protect personal information deals with not only disclosure and use of information, which confidentiality rules is about, but also collection and retention process, access to and correction and care of information and even destruction of information. Amid unprecedented theft of personal data in several national banks and other serious leakage reported recently, this paper is going to contemplate the scope and application of the duty to protect personal information with hope to contribute to starting discussion on it.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.257-263
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• 2005

Short-circuit rotor windings on a generator causes unstable oscillation of unbalance of flux, asymmetrical heat. In order to prevent serious accidents of short-circuit rotor windings, it is important to study the shorted-turn diagnosis method for rotor windings of the generator. To improve the defects of the diagnosis with sensors, the new sensorless method for rotor shorted-turn diagnosis is proposed, which is to measure the electrical values of the voltage and current at the generator and then to detect if the shorted-turned phenomena would occurred. For the feasibility of the suggested method the theoretical results are shown in the aspects of the air-gap flux density, the flux leakage, the generated output voltage and the shorted field current through the digital simulation. Also the possibility of decision for the suggested sensorless method could be shown in this paper.

• Journal of the Microelectronics and Packaging Society
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• v.10 no.3
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• pp.89-98
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• 2003

The electrical and mechanical properties of sputtered Cu(Mg) films are investigated for highly reliable interconnects. The roughness, adhesion, hardness and resistance to thermal stress of Cu(Mg) film annealed in vacuum at $400^{\circ}C$ for 30min were improved than those of pure Cu film. Moreover, the flat band voltage(V$_{F}$ ) shift in the Capacitance-Voltage(C-V) curve upon bias temperature stressing(BTS) was not observed and leakage currents of Cu(Mg) into $SiO_2$ were three times less than those of pure Cu. Because Mg was easy to react with oxide than Cu and Si after annealing, the Mg Oxide which formed at surface and interface served as a passivation layer as well.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.306.2-306.2
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• 2014

전자기기의 휴대성과 이동성이 강조되고 있는 현대사회에서 비휘발성 메모리는 메모리 산업에 있어 매우 매력적인 동시에 커다란 잠재성을 지닌다. 이미 공정의 한계에 부딪힌 Flash 메모리를 대신하여 10nm 이하의 공정이 가능한 상변화 메모리(Phase-Change Memory, PRAM), 스핀 주입 자화 반전 메모리(Spin Transfer Torque-Magnetic RAM, STT-MRAM), 저항 변화 메모리(Resistive Random Access Memory, ReRAM)가 차세대 비휘발성 메모리 후보로서 거론되고 있으며, 그 중에서도 ReRAM은 빠른 속도와 낮은 소비 전력, CMOS 공정 호환성, 그리고 비교적 단순한 3차원 적층 구조의 특성으로 인해 활발히 연구되고 있다. 특히 최근에는 질화물 또는 질소를 도핑한 산화물을 저항변화 물질로 사용하는 ReRAM이 보고되고 있는데, 이들은 동작전압이 낮을 뿐만 아니라 저항 변화(Resistive Switching, RS) 과정에서 일어나는 계면 산화를 방지할 수 있으므로 ReRAM의 저항 변화 재료로서 각광받고 있다. 그러나 Cell 단위의 ReRAM 소자를 Crossbar Array 구조에 적용시켰을 때 주변 Cell과의 저항 상태 차이로 인해 전류가 낮은 저항 상태(LRS)의 Cell로 흘러 의도치 않은 동작을 야기한다. 이와 같이 누설 전류(Leakage Current)로 인한 상호간의 간섭이 일어나는 Cross-talk 현상이 존재하며, 공정의 간소화와 집적도를 유지하면서 이 문제를 해결하는 것은 실용화하기에 앞서 매우 중요한 문제이다. 따라서, 본 논문에서는 Read 동작 시 발생하는 Cell과 Cell 사이의 Cross-talk 문제를 해결하기 위해 자가 정류 특성(Self-Rectifying)을 가지는 실리콘 질화물/알루미늄 질화물 이중층(Si3N4/AlN Bi-layer)으로 구성된 ReRAM 소자 구조를 제안하였으며, Sputtering 방법을 이용하여 제안된 소자를 제작하였다. 전압-전류 특성 실험결과, 제안된 구조에 대한 에너지 밴드 다이어그램 시뮬레이션 결과와 동일하게 Positive Bias 영역에서 자가 정류 특성을 획득하였고, 결과적으로 Read 동작 시 발생하는 Cross-talk 현상을 차단할 수 있는 결과를 확보하였다.