• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.25-28
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• 2008

The fuel cell system is environment-friendly and energy efficient system. Especially, the fuel cell cogeneration systems providing heat and electricity to buildings have been developed and applied to a lot of sites in the world to cope with the global warming and $CO_2$ emission problem. This paper presents the result of study on the economic evaluation with super-micro fuel cell (SMFC) cogeneration system by varying the floor area ($132m^2{\sim}331m^2$) of the house, whose system capacity ranges from 0.10 kWe to 0.50 kWe. The electricity demand, heat demand, saved energy cost, and the simple pay-back period have been simulated for the various capacities of fuel cell cogeneration system. As a result, this study suggests the fuel cell system's capacity decision strategy for a given house area. Contrary to conventional design assumptions, the smaller capacity fuel cell cogeneration system is appropriate for the house of large floor area to defense the progressive electricity tax, and the larger capacity fuel cell cogeneration system is appropriate for the house of small floor area to sell the electricity.

• 동의신경정신과학회지
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• 제8권2호
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• pp.63-84
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• 1997

The questionnaire which was based on the characteristics of psychological and physiological symptoms of Hwabyung patients was distributed to Hwabyung patients and normal control group. The following results were obtained. 1. It was observed in this study that the rate of occurrence of Hwabyung was higher in female and the people with lower economical and educational background. And this result was in accordance with the previous studies. 2. The personality, defense mechanism and coping strategy of Hwabyung patients was found to be inclined to yin(陰) disposition in this study. 3. Family life of Hwabyung patients was found to be worse than that of normal control group in every respect. 4. In terms of evaluation of their lives, the emotion of Hwabyung patients was characterized as Hahn(恨). And it is postulated that this emotional complex falsifies the reaction of Ki(氣) to the seven emotions(七情).

• Journal of Microbiology and Biotechnology
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• 제28권2호
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• pp.181-189
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• 2018

Candida albicans is a major pathogenic fungus in humans, and meets at first the innate immune cells, such as macrophages, in its host. One important strategy of the host cell to kill C. albicans is to produce reactive oxygen species (ROS) by the macrophages. In response to ROS produced by the macrophages, C. albicans operates its defense mechanisms against them by expressing its oxidative stress response genes. Although there have been many research studies explaining the specific transcription factors and the expression of the oxidative stress genes in C. albicans, the regulation of the oxidative stress genes by chromatin structure is little known. Epigenetic regulation by the chromatin structure is very important for the regulation of eukaryotic gene expression, including the chromatin structure dynamics by histone modifications. Among various histone modifications, histone acetylation is reported for its direct relationship to the regulation of gene expression. Recent studies reported that histone acetyltransferases regulate genes to respond to the oxidative stress in C. albicans. In this review, we introduce all histone acetyltransferases that C. albicans contains and some papers that explain how histone acetyltransferases participate in the oxidative stress response in C. albicans.

• 한국IT서비스학회지
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• 제15권2호
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• pp.157-167
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• 2016

Task environment for enterprises and public institutions are moving into cyberspace-based environment and structing the LTE wireless network. The applications "App" operated in the LTE wireless network are mostly being developed with Android-based. But Android-based malwares are surging and they are the potential DDoS attacks. DDoS attack is a major information security threat and a means of cyber attacks. DDoS attacks are difficult to detect in advance and to defense effectively. To this end, a DMZ is set up in front of a network infrastructure and a particular server for defensive information security. Because There is the proliferation of mobile devices and apps, and the activation of android diversify DDoS attack methods. a DMZ is a limit to detect and to protect against DDoS attacks. This paper proposes an information security method to detect and Protect DDoS attacks from the terminal phase using a Preemptive military strategy concept. and then DDoS attack detection and protection app is implemented and proved its effectiveness by reducing web service request and memory usage. DDoS attack detection and protecting will ensure the efficiency of the mobile network resources. This method is necessary for a continuous usage of a wireless network environment for the national security and disaster control.

• 한국시뮬레이션학회논문지
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• 제27권2호
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• pp.101-114
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• 2018

무인 비행체의 실시간 경로계획 생성 시 최적의 경로를 찾기 위한 다양한 연구가 진행되어 왔다. 본 논문에서는 진화알고리즘을 통한 무인비행체의 경로계획 생성을 수행하고, 이를 에이전트 기반 시뮬레이션 환경에서 구현 및 테스트가 가능함을 검증하였다. 이를 위해, Repast toolkit에 JGAP 패키지를 탑재하여 Java 기반의 유전 알고리즘 프로그래밍을 통한 무인 비행체의 경로 계획을 생성하였고, 해당 결과를 에이전트 기반으로 시뮬레이션을 수행하였다. 본 논문에서는 에이전트 기반 시뮬레이션 소프트웨어를 소프트웨어 공학 개발 생명주기에 맞춰 문서화하여 설계 및 구현되었으며, 에이전트 모델링 설계는 자동화, 적응성 및 에이전트 간의 상호 작용에 초점을 맞추었다. 또한, 시뮬레이션을 통해 에이전트 기반 환경에서 설계한 모델 및 시나리오를 검증하여 다수의 비행 에이전트에 내재된 동적 경로계획 알고리즘이 실시간으로 자율적인 경로 생성이 가능함을 증명하였다.

• 융합보안논문지
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• 제19권4호
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• pp.35-41
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• 2019

북한의 전략을 고려할 때, 개전 상황시 북한의 최우선 타격 목표는 공군을 무력화하는 공군 활주로일 가능성이 높다. 이에 대한 대응 방안으로 비상 활주로와 활주로 긴급 복구 작전이 있다. 하지만 비상 활주로는 주로 비상 착륙, 연료 공급, 재무장로 이용된다. 활주로 긴급 복구 작전도 북한의 위협적인 미사일 수준을 고려할 때 복구 시간 등 몇 가지 한계점이 있기에 활주로 폭파에 신속히 대응할 수가 없다. 본 연구에서는 먼저 북한의 미사일 위협 수준을 판단한다. 이후, 활주로 폭파의 차세대 대응방안인 이동식 활주로의 개념과 한계를 제시하며 기존 대응 방안과의 비교를 통해 이동식 활주로 도입의 필요성을 제시한다.

• Biomolecules & Therapeutics
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• 제26권1호
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• pp.57-68
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• 2018

Nuclear factor E2-related factor 2 (NRF2) plays an important role in redox metabolism and antioxidant defense. Under normal conditions, NRF2 proteins are maintained at very low levels because of their ubiquitination and proteasomal degradation via binding to the kelch-like ECH associated protein 1 (KEAP1)-E3 ubiquitin ligase complex. However, oxidative and/or electrophilic stresses disrupt the KEAP1-NRF2 interaction, which leads to the accumulation and transactivation of NRF2. During recent decades, a growing body of evidence suggests that NRF2 is frequently activated in many types of cancer by multiple mechanisms, including the genetic mutations in the KEAP1-NRF2 pathway. This suggested that NRF2 inhibition is a promising strategy for cancer therapy. Recently, several NRF2 inhibitors have been reported with anti-tumor efficacy. Here, we review the mechanisms whereby NRF2 is dysregulated in cancer and its contribution to the tumor development and radiochemoresistance. In addition, among the NRF2 inhibitors reported so far, we summarize and discuss repurposed NRF2 inhibitors with their potential mechanisms and provide new insights to develop selective NRF2 inhibitors.

• 융합보안논문지
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• 제15권1호
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• pp.69-82
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• 2015

고도화되고 지능화가 예상되는 사이버 침해대응에 대해 효율적으로 대응키 위해서는 악성코드의 공격에 대해 기존 방어적 대응형태에서 공격적 전환개념이 요구되기에 이러한 환경을 근간으로 연구한 결과 기존의 OS, APPLICATION SYSTEM 등의 각 영역별 SINGLE-MODE 체계의 구조대비 Real-time에 의한 공통 전수 취약점 탐지 분석 개념으로 다단계기반의 탐지 및 분석개념(MPSM)을 연구하였다. 동시에 필요시 해당 정보자산과 직접적인 단독접속형태의 취약점 탐지 및 분석을 위해 API 기반의 전용하드웨어 플랫폼형태의 방안이 요구되어 짐과 동시에 이를 위해서는 H/W 및 S/W의 분리된 현재와 같은 2중화된 형태가 아닌 일체형의 H/W 타입의 플랫폼구조 기반 형태로 설계됨과 동시에 병행되어 빅데이타 분석에 의한 정보보안의 포렌직 측면을 고려할 시 항시 모니터링 되고 관리할 수 있는 구조로 연동 설계 등에 대해 제안하였다.

• 한국IT서비스학회지
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• 제15권1호
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• pp.67-79
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• 2016

This study aims to present the necessary elements that should be part of South Korea's National Defense Strategy against the recent North Korean cyber-attacks. The elements proposed in this study also reflect the recent trend of cyber-attack incidents that are happening in the Unites States and other countries and have been classified into the three levels of cyber incidents: cyberwarfare, cyberterrorism and cybercrime. As such, the elements proposed are presented in accordance with this classification system. In order to properly take into account the recent trend of cyber-attacks perpetrated by North Korea, this paper analyzed the characteristics of recent North Korean cyber-attacks as well as the countermeasures and responses of South Korea. Moreover, by making use of case studies of cyber-attack incidents by foreign nations that threaten national security, the response measures at a national level can be deduced and applied as in this study. Thus, the authors of this study hope that the newly proposed elements here within will help to strengthen the level of Korea's cyber security against foreign attacks, specifically that of North Korea such as the KHNP hacking incidents and so on. It is hoped that further damage such as leakage of confidential information, invasion of privacy and physical intimidation can be mitigated.

• International Journal of Aeronautical and Space Sciences
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• 제16권3호
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• pp.394-406
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• 2015

In this work, an efficient aircraft landing simulation strategy is proposed to develop an efficient and reliable hard-landing monitoring procedure. Landing stage is the most dangerous moment during operation cycle of aircraft and it may cause structural damage when hard-landing occurs. Therefore, the occurrence of hard-landing should be reported accurately to guarantee the structural integrity of aircraft. In order to accurately determine whether hard-landing occurs or not from given landing conditions, full nonlinear structural dynamic simulation can be performed, but this approach is highly time-consuming. Thus, a more efficient approach for aircraft landing simulation which uses a hierarchical aircraft landing model and an extended inertia relief technique is proposed. The proposed aircraft landing model is composed of a multi-body dynamics model equipped with landing gear and tire models to extract the impact force and inertia force at touch-down and a linear dynamic structural model with an extended inertia relief method to analyze the structural response subject to the prescribed rigid body motion and the forces extracted from the multi-body dynamics model. The numerical examples show the efficiency and practical advantages of the proposed landing model as an essential component of aircraft hard-landing monitoring procedure.