• 한국위성정보통신학회논문지
• /
• 제8권2호
• /
• pp.50-55
• /
• 2013

스마트그리드는 전력망에 정보기술을 접목하여, 전력공급자와 소비자가 양방향으로 실시간 정보를 교환, 에너지효율을 최적화하며 새로운 부가가치를 창출하는 차세대 전력망이다. 본 논문에서는 스마트그리드 환경 하에서 수요반응 통신시스템 중 프로토콜에 사용되는 정보 통신 모델 개념에 대하여 서술하였다.

• 한국정보통신설비학회:학술대회논문집
• /
• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
• /
• pp.559-562
• /
• 2008

In this paper we propose a lock-in detection method for portable sensor systems and demonstrate with the portable detection module that has high sensitivity and robustness against the noise. The simple portable sensor module is manufactured using MCU(Micro Contorl Unit), OPAMP, MOSFET and a pair of infrared sensor. Manufactured sensor module is testified in the noisy environment caused by an external light and an white noise source. Without any type of band pass filters, we recover a signal of 33 $mV_{p-p}$ in 80 $mV_{p-p}$ white noise and get the DR(Dynamic Reserve) of 14 dB.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년 영문 학술대회
• /
• pp.583-588
• /
• 2008

A spacecraft propulsion system utilizing the energy of the solar wind was reviewed. The first plasma sail concept was proposed by Prof. Winglee in 2000, and that was called M2P2(mini-magnetospheric plasmapropulsion). However, the first M2P2 design adopting a small(20-cm-diamter) coil and a small helicon plasma source design was criticized by Dr. Khazanov in 2003. He insisted that: 1) MHD is not an appropriate approximation to describe the M2P2 design by Winglee, and with ion kinetic simulation, it was shown that the M2P2 design could provide only negligible thrust; 2) considerably larger sails(than that Winglee proposed) would be required to tap the energy of the solar wind. We started our plasma ssail study in 2003, and it is shown that moderately sized magnetic sails can produce sub-Newton-class thrust in the ion inertial scale(${\sim}70$ km). Currently, we are continuing our efforts to make a feasibly sized plasma sail(Magnetoplasma sail) by optimizing the magnetic field inflation process Winglee proposed.

• Biomolecules & Therapeutics
• /
• 제27권2호
• /
• pp.145-151
• /
• 2019

Methamphetamine (METH) acts strongly on the nervous system and damages neurons and is known to cause neurodegenerative diseases such as Alzheimer's and Parkinson's. Flavonoids, polyphenolic compounds present in green tea, red wine and several fruits exhibit antioxidant properties that protect neurons from oxidative damage and promote neuronal survival. Especially, epicatechin (EC) is a powerful flavonoid with antibacterial, antiviral, antitumor and antimutagenic effects as well as antioxidant effects. We therefore investigated whether EC could prevent METH-induced neurotoxicity using HT22 hippocampal neuronal cells. EC reduced METH-induced cell death of HT22 cells. In addition, we observed that EC abrogated the activation of ERK, p38 and inhibited the expression of CHOP and DR4. EC also reduced METH-induced ROS accumulation and MMP. These results suggest that EC may protect HT22 hippocampal neurons against METH-induced cell death by reducing ER stress and mitochondrial damage.

• 한국발생생물학회지:발생과생식
• /
• 제23권2호
• /
• pp.101-110
• /
• 2019

Melatonin is a pineal hormone that is synthesized and released at night under the light and dark cycles of a day. Its effects on the reproductive activities have well been established by the administration through various routes in photoperiodic animals. It was also identified in plants and named phytomelatonin. The capacity of the phytomelatonin was investigated in this investigation whether it affects the reproductive function in male golden hamster. As expected, animals housed in long photoperiod (long photoperiod, LP>12.5 hours of lights in a day) had large testes and animals kept in short photoperiod ($$SP{\leq_-}12.5$$ hours of lights in a day) showed remarkably reduced testes. The dietary supplement with melatonin itself induced the complete involution of testes. Pistachios that were reported to contain a large amount of melatonin demonstrated no effects at all in male golden hamsters. These results suggest that dietary supplement containing melatonin-rich foodstuff used in this investigation may not be enough to affect the reproductive endocrine system in male golden hamsters.

• 자동차안전학회지
• /
• 제15권4호
• /
• pp.71-78
• /
• 2023

This study presents the direction of data triggers and elements to be recorded in automated vehicles in the future in relation to the event data recorder (EDR) and data storage system for automated driving (DSSAD). It does not distinguish between the EDR and DSSAD, but suggests data triggers and elements in preparation for overall automated vehicle accidents and dangerous situations. To propose, the current status of discussions on EDR/DSSAD internationally and the case of investigating accidents with automated vehicles under temporary driving licenses in Korea were analyzed. Based on the analysis, the direction of data triggers and elements of the EDR/DSSAD of automated vehicles were presented.

• Nonlinear Functional Analysis and Applications
• /
• 제29권2호
• /
• pp.597-620
• /
• 2024

In this study, the conformable fractional derivative(CFD) of order 𝝔 in conjunction with the LC operator of orderρ is used to develop the model of the transmission of the A(H1N1) influenza infection. A brand-new A(H1N1) influenza infection model is presented, with a population split into four different compartments. Fixed point theorems were used to prove the existence of the solutions and uniqueness of this model. The basic reproduction number R₀ was determined. The least and most sensitive variables that could alter R₀ were then determined using normalized forward sensitivity indices. Through numerical simulations carried out with the aid of the Adams-Moulton approach, the study also investigated the effects of numerous biological characteristics on the system. The findings demonstrated that if 𝝔 < 1 and ρ < 1 under the CFD, also the findings demonstrated that if 𝝔 = 1 and ρ = 1 under the CFD, the A(H1N1) influenza infection will not vanish.

• 대한디지털의료영상학회논문지
• /
• 제9권2호
• /
• pp.5-9
• /
• 2007

As developing the medical treatment image portion with the change of these times, PACS, which is able to digitalize image portion data, has a lot of data-based image data. Applying this PACS, we would like to settle down RNSXI(real-name shooting X -ray of inspector) system. We interviewed with P ACS's operators of university hospitals which is using PACS in Seoul about the present conditions whether using of RNSXI or not. And we inquired the RNSXI equipments, applying PACS database, and Interface conditions undertook to do in our hospital. All university hospitals in Seoul are set up the P ACS system. But no hospital use the RNSXI. In our hospital, we can check inspector' name or initials who exposure x-ray with the PACS Viewer by looking over equipments(CR, DR, US, MG, MR, CT) and Interface of the DICOM Header data. However, some equipments like RF and Angio can not check inspector' name or initials. Under the Film/System environment, RNSXI system has been used frequently like that inspector's signature or initial added to a patient data. Though the digital medical treatment was developed, RNSXI system was declined. It is necessary to using RNSXI system in order to improving radiologists' rights, even if it is not under the application of the medical treatment image laws. If RNSXI system use, radiologists should specialize in their major and the Repeat rate should be reduced. In environment of PACS, RNSXI system can be used by linking both the equipments and the Interface with a production enterprise of P ACS. Therefore RNSXI system applying the P ACS datebase should settle down in our medical system for being provided lots of data.

• 한국정보통신학회논문지
• /
• 제8권2호
• /
• pp.245-249
• /
• 2004

본 논문에서는 대역제한필터(BL-PSF)를 이용하는 OFDM/QPSK-DMR 시스템에 적합한 클럭 복원 알고리즘을 제안하고 OFDM/QPSK-DMR 시스템과 단일 주파수방식의 DMR 시스템의 클럭 위상에러분산을 비교 분석하였다. 기존 Windowing을 적용하는 OFDM/QPSK-DMR 시스템은 수신 클럭의 위상을 동기 시키기 위해 훈련심볼 또는 CP(Cyclic Prefix)등의 잉여 데이터를 사용하나 본 논문의 DMR 시스템은 전송효율을 향상시키기 위해 잉여 데이터를 삽입하지 않고 단일 주파수방식의 클럭복조방식을 채택하였다. 이 방식은 간단하게 구현할 수 있는 장점을 갖는다. 제안한 클럭 복원 알고리즘은 AWGN 환경에서 단일 주파수방식의 DMR 시스템과 성능 열화 없이 동일한 클럭 위상 에러 분산값을 갖는 것을 시뮬레이션 결과로 확인하였다.

• 인터넷정보학회논문지
• /
• 제2권3호
• /
• pp.19-25
• /
• 2001

컴퓨터를 이용한 교육 시스템은 1950년대 말 일리노이 대학의 Donald Bitzer박사에 의해 구상되어 1961년 PLATO 시스템이 개발된 이래 지난 30여년 동안 다각적인 연구가 이루어져 왔고, 특히, 인터넷과 정보통신 기술의 발달은 WWW기반의 원격교육 시스템의 개발과 발전을 진일보시켰으며, 이들 시스템들은 기존의 교육 패러다임을 변모시키는 새로운 형태의 교육체계 구현을 통해 교육 현장에 커다란 기여를 하고 있다. 본 논문은 WWW기반 기술 중 능동적 정보전달 방식인 Push 기술을 기존 원격교육 시스템에 접목하여 학습자가 인터넷의 학습 DB에 접속하지 않고도 학습 내용을 제공받을 수 있고, 새로운 학습정보를 실시간적으로 파악할 수 있는 Push 기반 원격교육시스템을 제안한다. 또한, 학습자의 다양한 수준에 맞는 문제의 처리와 문항 분석이 가능한 수준별 문항평가 알고리즘을 통해 학습자의 학습수준에 적합한 문항 평가 이루어지도록 설계하였다.