Earticle

In this study, we investigate the phenomenon where momentarily melted copper is scattered from the power source side to the load side during a short-circuit in electrical wiring, caused by arc sparking at the fault. This results in different short-circuit shapes on the power source side compared to the load side. Additionally, we theoretically analyze physical phenomena such as the Lorentz force acting on the electric wire during a short-circuit. By sharing these experimental and theoretical findings, we aim to better understand the mechanism of short-circuit formation and utilize this knowledge to pinpoint specific ignition points in fire investigation contexts.

분산 서비스 거부 공격(DDoS Attack, Distributed Denial of Service Attack) 수법의 진화는 탐지 과정에서의 어려움을 가중시켰다. 기존 피해자측 탐지 방식의 한계로 인해 발생하는 문제를 극복하기 위한 솔루션 중 하나가 소스측 탐지 기법이었다. 그러나 네트워크 트래픽의 불규칙성으로 인한 성능 저하 문제가 존재하였다. 이 문제를 해결하기 위해 인공지능을 기반으로 한 여러 노드 간의 협업 네트워크를 활용하여 공격을 탐지하려는 연구가 진행되었다. 기존의 방법들은 특히 높은 버스트(Burstness)와 지터(Jitter)의 비선형적 트래픽 환경에서 한계를 보였다. 이러한 문제점을 극복하기 위해 본 논문에서는 어텐션(Attention) 메커니즘을 도입한 협업형 소스측 DDoS 공격 탐지 기법을 제시한다. 제안하는 방식은 여러 소스에서의 탐지 결과를 집계하여 각 지역에 가중치를 할당하며, 이를 통해 전반적인 공격 및 특정 소수 지역에서의 공격을 효과적으로 탐지할 수 있다. 특히, 비선형적인 트래픽 데이터셋에서 약 6% 수치의 낮은 가양성(False Positive)과 최대 4.3% 수치가 향상된 높은 탐지율을 보이며, 기존 비선형적 트래픽 환경에서 한계를 보였던 방법들에 비해 소수 지역의 공격 탐지 문제에 대한 개선도 확인할 수 있다.

The evolution of the Distributed Denial of Service Attack(DDoS Attack) method has increased the difficulty in the detection process. One of the solutions to overcome the problems caused by the limitations of the existing victim-side detection method was the source-side detection technique. However, there was a problem of performance degradation due to network traffic irregularities. In order to solve this problem, research has been conducted to detect attacks using a collaborative network between several nodes based on artificial intelligence. Existing methods have shown limitations, especially in nonlinear traffic environments with high Burstness and jitter. To overcome this problem, this paper presents a collaborative source-side DDoS attack detection technique introduced with an attention mechanism. The proposed method aggregates detection results from multiple sources and assigns weights to each region, and through this, it is possible to effectively detect overall attacks and attacks in specific few areas. In particular, it shows a high detection rate with a low false positive of about 6% and a high detection rate of up to 4.3% in a nonlinear traffic dataset, and it can also confirm improvement in attack detection problems in a small number of regions compared to methods that showed limitations in the existing nonlinear traffic environment.

의약품 부작용과 같이 국민의 건강과 밀접한 관련이 있고, 전문적인 이슈의 경우 언론 보도는 국민들의 위기 대응과 정부의 위기관리에 영향을 미칠 수 있다는 점에서 중요하다. 이 연구는 의약품 부작용과 관련된 언론 보도를 주요 주제, 정보원, 위기 책임 귀인, 프레임을 분석하고 언론의 주목을 받은 의약품 부작용보도에 대해 네트워크 분석을 실시해 정부의 위기관리 방안을 제시했다. 일간지, 경제지, 전문지의 보도에 차이가 있었는데, 일간지는 부작용 발생과 같은 위기 발생을 중심으로, 경제지는 제약업계 관련된 기사를, 전문지는 의약품 정책을 비판하는 기사 중심으로 보도했다. 의약품 부작용과 관련된 주요 정보원은 국회의원이었다. 위기의 책임을 언급한 기사는 적었지만, 위기 해결의 주체에 대해서는 의약품을 생산한 업체가 해결해야 한다는 기사가 많았지만 전문지의 경우에는 정부가 문제를 해결해야 한다고 했다. 네트워크 분석을 통해 기사에서 중요하게 언급된 단어를 찾고, 단어와 단어의 관계 분석으로 기사에서 전달하고자 하는 의미를 찾았다. 이 연구는 내용분석과 네트워크 분석을 통해 의약품 부작용 기사를 분석하고 정부의 위기 커뮤니케이션 관점에서 공중별 정부의 위기 대응 방안을 고려해봤다는 데 의의가 있다.

The side effects of drug is closely linked to the people's health and professional. In this case, press report is very important in evaluating the side effects of drug and people's attitude of government's health policy. This study analyzed press report on the side effects of drug based on the main theme, source, responsibility attribution on crisis, frame and network analysis. Theses is a difference of main theme between the press. Daily newspaper focused on the occurrence of crisis and economical newspaper focused on the manufacture company. Professional paper focused on the criticizing of the health policy. The main source of the press on the side effects of drug is the Congressman. There are few articles which mentions about the crisis responsibility. However most articles mentioned that the subject of crisis solutions is the manufacturer. This study found the main meaning by network analysis. This study highlighted the government's crisis management based on the result of content analysis and network analysis.

This paper presents a Ka-band low-noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) using a GaN high-electron-mobility transistor (HEMT) structure designed to minimize gate-source parasitic capacitance (C_gs). In conventional multigate GaN HEMTs, internal source interconnects tie split sources, increasing parasitic coupling near the gate and degrading the minimum noise figure (NF_min) at millimeter-wave frequencies. To overcome this limitation, an external source interconnect is routed outside the active region, effectively suppressing gate-side parasitics and reducing C_gs, without compromising circuit integrity or layout compactness. The proposed five-stage common-source LNA MMIC, fabricated using ETRI's 0.15 ㎛ GaN-on-SiC process, achieves a gain of 23-28 dB and a noise figure of 2.1-2.3 dB across 26-30 GHz. Compared with recently reported Ka-band GaN LNA MMICs, the design attains figures of merit: FoM₁ = 724 GHz/mm² and FoM₂ = 0.72 GHz/mW·mm². These improvements result from the reduced C_gs enabled by the external source interconnect and compact layout, confirming the suitability of the proposed HEMT structure for high-performance millimeter-wave frontend receivers requiring low-noise and efficient integration.

본 논문은 전원단과 부하단사이에 GTO 사이리스터 브리지가 설치된 단상 DC 리액터타입을 적용한 고온초전도 사고전류제한기 동작특성에 대해 분석하였다. GTO 사이리스터 브리지가 설치된 DC 리액터 타입 FCL(FAULT CURRENT LIMITER)은 평상시에 초전도코일에 전기에너지를 저장한다. 전원단의 사고로 인해 전력공급이 중단되었을 경우 FCL은 부하에 저장된 에너지를 공급할 수 있을 뿐 아니라 부하단 사고로 인한 사고전류 제한기능을 수행하게 되는데 이와 같은 동작은 GTO 사이리스터를 제어함으로서 가능해진다.

Recently, according to developing industry and life style, power consumption have been increased year after year. Currently these much power demand from power consumer is weakening the allowable power reserve margin in summer. As one of the remedies about this problem, the small scale utility interactive photovoltaic system(UIPVS) is considered for auxiliary power source. For this system one of problems to be solved technically, system operating power factor. Generally in case of small scale system, system is operated in unity power factor. But this unity power factor operating mode decrease power factor viewed from utility because UIPVS supply active power to utility. Therefore this paper propose UIPVS with power factor correcting function and this system is analyzed.

The application field of photovoltaic system has been increased widely. In the application of photovoltaic system, the utility interactive photovoltaic system(UIPVS) has benefits of not only the home energy saving in domestic system but also reduction of peak power which threaten the capacity of power plant equipment when the maximum power consumption is occurred in daytime. This paper represents the effect of the nonlinear AC load which connected to the UIPVS with parallel connection and introduces the active power filtering(APF) techniques to the UIPVS for the reactive power compensation. The enhancement of source side power quality using APF algorithm is verified using simulation.

Most LV customers have been applying three-phase four-wire electric distribution system which supplies 1-phase and 3-phase load concurrently. Due to its structural simplicity, This system is easy to run. But it can also cause many problems from the unbalance, such as reduced output, increased loss etc. Also the unbalance in the load side causes the unbalance in the source side; it may lower the stability of the whole power system. In this paper, we propose the Y-Tz transformer winding method to reduce the current unbalance in the source side. Efficiency of this method was proven through the simulation and verification experiment.

A new current source inverter (CSl) with dc-side commutation and load-side energy recovery circuit is proposed with analysis and explanation of the circuit operation. Proposed inverter overcomes the most drawbacks of the conventional CSI's - high device voltage stress, low operating frequency range, large commutation capacitance, etc. - by employing simultaneous recovery and commutation concept. The new CSI employs only one commutation capacitor and it can be built with considerably low cost. The commutation energies are temporarily stored into a large dc capacitor and recovered to the load side, thus the device voltage stress is low and the efficiency is high in the proposed inverter. Computer simulation results are given at the steady state, and a guideline determining the commutation circuit is given.

In the current source type active power filter, the DC current source is implemented using an inductor with large inductance by maintaining the inductor current constantly. In this case, to compensate the loss of the switching devices of the power converter and the inductor, some real power should be supplied to the filter from the source. This process is analyzed through the equivalent circuit which expresses the loss of the switching devices and the inductor with the equivalent resistor R. This work discusses the validation of this DC side equivalent circuit and points out the problems, through the experiments using the experimental active power filter with 220V, 10KVA ratings, and suggests a more accurate equivalent circuit which puts the saturation voltage of the power transistors and the threshold voltage of the diodes into consideration.

노자영은 ‘백조’ 동인이며, 『사랑의 불꽃』, 『반항』 등의 저작·출판으로 1920년대 중반 상업적 성공을 거둔 작가다. 노자영은 ‘연애’를 다룬 작품으로 상업적이며 대중적인 성공을 거두었지만 거듭된 표절 의혹으로 문인으로서 위신은 잃었다. 외국 작품의 번역에 버젓이 자신의 이름을 작자로 덧붙여 지면에 발표한 것이 번번이 다른 문인에 의해 밝혀진 것이다. 또한 대중의 인기를 누린 작품이 문단에서 요구하는 눈높이에 미달한다는 것도 문제가 되었다. 노자영의 소설에는 부정의 정신과 대상에 대한 거리감각이 결여되어 있다는 것이 이유였다. 이러한 까닭으로 노자영은 문단에서 ‘배제’되었는데, 이는 1920년대 문단이 제도화되고 전문화되며 소설계가 재편되는 것을 상징적으로 보여준다. 노자영의 소설은 비록 노자영과 함께 문단에서 ‘배제’되었지만 청춘 남녀들의 사랑을 통속적으로 다루는 딱지본 장정의 대중소설, 즉 ‘딱지본 대중소설’로 전화(轉化)되어 대중 독서 시장에서는 더욱 활발히 독자들에게 읽혔다. 그만큼 ‘연애’ 담론에 친숙한, 근대적 교육을 받은 독자층이 증가하였기 때문이다. 그런 점에서 ‘딱지본 대중소설’은 당대 문화의 지층을 탐사하는 데 요긴할 뿐만 아니라 문학사 뒷면의 문학 실태를 확인할 수 있는 텍스트이다. 한편 이들 ‘딱지본 대중소설’의 작자는 습작기의 작가나 학비를 벌어야 하는 학생들이었던 것으로 추정된다. 그 예로 이무영과 월파 김상용을 들 수 있다. 특히 김상용의 『동정의 루』는 노자영의 소설을 참조하여 창작되었는데 이것을 통해 당대 ‘딱지본 대중소설’이 노자영 소설로부터 받은 영향과 ‘딱지본 대중소설’의 존재 방식을 확인할 수 있다.

No, Ja-Young is a writer who achieved commercial success with the flame of love , resistance in 1920’s. But he lost prestige as a writer because of the frequent plagiarism. Fellow writers didn’t allow that he was a writer, for they thought that he wrote less than worthy novels. No was excluded from Literary circle, that is not the problem of a writer but the symbolic event which means the specialization of Literary circles at that time. No’s novels had something to do with ‘sin-pa-so-sul’, that is dime novel and is made of ‘ddak-ji-bon’. The former provided a triggering event and the latter were written much after the model of narration and sensibility of the former. They fell to be recoded but was present as an undercurrent in the history of literature. The more it is far from ‘sin-pa-so-sul’, the more it is a good novel. In that sense, writers regarded ‘sin-pa-so-sul’ as reference model from the denial side. Therefore, the study of ‘sin-pa-so-sul’ provides new view point of prospecting the history of Korean modern literature.